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[Display omitted] • High carrier migration efficiency of the double direct bandgap S-scheme heterojunction is obtained. • Strong intrinsic electric fields promote efficient separation and migration of photogenerated charges. • Graphdiyne effectively regulate the d-band center of Co atom. • Introducing graphdiyne effectively increases electron state density at the Fermi level in Co 2 VO 4. The selection of direct band gap semiconductors with high-efficiency electron transitions and the rational adjustment of the d-band center of transition metal atoms can effectively enhance photocatalytic hydrogen evolution. Based on this premise, the double direct band gap graphdiyne/Co 2 VO 4 S-scheme heterojunction was designed via an immersion method. DFT calculation, in-situ XPS and EPR analysis not only provided support for the formation of graphdiyne /Co 2 VO 4 S-scheme heterojunction but also demonstrated that Co maybe served as the most efficient active site for hydrogen evolution. Furthermore, the design of S-scheme heterojunction effectively prolongs the carrier lifetime of the photocatalyst, resolves the deficiency in high electron-hole pair recombination rate of direct band gap semiconductors, and maintains its efficient electronic transition. PDOS analysis revealed that the interaction between graphdiyne and Co 2 VO 4 at the microscopic interface tends to modulate the d-band center of cobalt atoms, resulting in a decrease in electron occupation on antibonding orbitals and consequently enhancing bonding stability at Co active sites. Moreover, introducing graphdiyne effectively increases electron state density near the Fermi level of Co 2 VO 4 , facilitating rapid migration of photogenerated charges. This study provides valuable insights into the regulating d-band centers of transition metal and the development of double direct band-gap S- scheme heterojunctions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mx-PEI-ZnO@Co 3 O 4 was prepared firstly as a pioneering CO 2 photoreduction catalyst. • CO and CH 4 yield can reach to 594.37 and 42.67μmol g−1 h−1. • PEI with rich amino groups was utilized as a potent linker to bolster CO 2 adsorption and strengthen interaction with Ti 3 C 2 through hydrogen bonding. • The enhanced performance can be attributed to improved light absorption, abundant active sites and unique S-scheme and Schottky double heterojunction facilitating effective charge transfer. The photocatalytic reduction of CO 2 into energy carriers holds significant industrial appeal, but achieving this process kinetically remains challenging due to the lack of well-designed catalysts. This study presents a novel 2D/3D nanostructured photocatalyst, developed by attaching a few-layer Ti 3 C 2 MXene to polyethylenimine (PEI)-modified ZnO@CO 3 O 4 nanocages, which are derived from a bimetallic zinc-cobalt ZIF. The resulting Mx-PEI-ZnO@Co 3 O 4 catalyst achieved impressive yields of CO and CH 4 at 594.37 and 42.67 μmol g−1 h−1, respectively, without the need for sacrificial agents and photosensitizers, and maintained remarkable stability across multiple cycles. These yields represent the highest performance for ZnO-based catalysts to date, with quantum efficiency at 380 nm reached up to 25.06 %. The unique S-scheme and Schottky junctions, along with enhanced CO 2 adsorption and hydrogen-bond interactions facilitated by the conductive PEI within the Ti 3 C 2 /ZnO/Co 3 O 4 double heterojunctions, effectively inhibit electron-hole recombination and significantly enhance CO 2 photoreduction performance. This study underscores the combined benefits of double heterojunction engineering, PEI-functionalized CO 2 uptake, and MXene co-catalyst integration within a single system, proposing a new approach for designing highly efficient photocatalysts for solar-driven CO 2 reduction in energy-efficient fuel production. [ABSTRACT FROM AUTHOR]

• A Cl doping strategy was used to enhance the PDT capabilities of Cu 2 O under visible light. • Cl doping can adjust the band structure of Cu 2 O for generating ROS and inhibit recombination. • Cl-Cu 2 O was used to create antibacterial food packaging films to extend fruit shelf life. • The film addresses food quality and safety concerns in perishable goods while ensuring biosafety. Microbial spoilage and pathogen contamination present significant challenges to food quality and safety. Incorporating photodynamic sterilization (PDT) into active packaging films, especially using white light-driven methods, is recognized as one of the most effective strategies to combat microbial contamination and extend shelf-life. Cuprous oxide (Cu 2 O) shows promise due to its suitable band gap for absorbing visible light, although its photocatalytic effectiveness is hindered by electron-hole recombination. In this study, a chlorine (Cl) doping strategy was investigated to enhance Cu 2 O's PDT capabilities under visible light. This approach aimed to improve Cu 2 O's band structure for generating reactive oxygen species (ROS) and to enhance charge carrier separation efficiency, thereby inhibiting recombination. The resulting Cl-doped Cu 2 O (Cl-Cu 2 O) exhibited enhanced antibacterial activity, which was integrated into a gelatin (Gel) and carboxymethylcellulose (CMC)-based food packaging film, referred to as the GC/Cl-Cu 2 O film. This innovative film provides a white light-driven active packaging solution designed to extend the shelf life of fruits by suppressing microbial growth. This approach not only addresses food safety concerns but also mitigates economic losses associated with food waste, offering a sustainable solution to enhance the quality and safety of perishable goods. [ABSTRACT FROM AUTHOR]

[Display omitted] • Solar illumination assists ferroelectric energy storage capacitors. • Introduced oxygen vacancy defects play key role in capturing the photogenerated carriers. • The energy storage of the BWNO flexible film shows 21.3% higher than the corresponding value under no light. • This work provides a scheme for clean optical energy storage and photoelectric application of dielectric capacitors. Different from traditional dielectric capacitors that only rely on polarization charges for energy storage, this work designs an intermediate band ferroelectric Bi 2 W 0.94 Ni 0.06 O 6- δ (BWNO) flexible film capacitor with strong photoelectric effect for collaborative energy storage by photoelectrons and polarization charges. Intermediate band as a springboard makes the photons with energy lower than the bandgap excite electron-hole pairs, which effectively improves the utilization rate of low-frequency photons under solar illumination. The photogenerated electrons are captured by the oxygen vacancies in BWNO, thereby inhibiting the recombination of electron-hole pairs and storing them. In the discharge process of the capacitor, the photogenerated electrons and holes are driven to the negative and positive plates respectively by the depolarization field, and flow to the load along with the shielding charges, completing the whole process of photoelectric energy storage. The BWNO flexible film under the full application of standard sunlight obtain an energy storage density of 18.8 J·cm−3, which is 21.3 % higher than the corresponding value under no light. This work provides a scheme for clean optical energy storage and photoelectric application of dielectric capacitors. [ABSTRACT FROM AUTHOR]

• PCN@AgI heterojunction facilitated charge transport and prevents recombination of electron-hole pairs. • PCN@AgI heterojunction generated sufficient ROS under visible light irradiation. • PCN@AgI heterojunction effectively combated bacteria including multi-drug resistant strains. • PCN@AgI heterojunction showed great promise for healing rat wound model with E. coli infection. Pathogenic bacterial infections have become a continuing threat to human health over the past decade, the development of novel antibacterial agents or strategies against drug-resistance bacteria is highly desirable. Although porphyrin-based metal organic frameworks (PCN) are important photosensitizers (PSs) for photodynamic antibacterial treatments, they are inefficient for killing gram-negative bacteria such as Escherichia coli. Herein, PCN@AgI heterojunction was prepared as a novel and potent multifunctional antibacterial agent to combat bacteria including drug-resistance bacteria such as extended-spectrum β-lactamase Escherichia coli (ESBL) under visible light irradiation in vitro , attributing to the cooperation of the generated ROS and released Ag+ as well as GSH-depleting ability. Compared to pristine PCN, the formation of heterojunction between AgI and PCN facilitated the sufficient separation of the produced electron- hole pairs, leading to enhanced photocatalytic antibacterial capability by producing sufficient ROS. Furthermore, its GSH-depleting ability due to its oxidase-like behavior further boosted its antibacterial capability. Significantly, in vivo studies demonstrated that PCN@AgI heterojunction could promote the healing of E. coli -infected wound on rice back with high biosafety. These findings manifested that PCN@AgI heterojunction was a good potential antibacterial therapeutic agent and may hold promise in bacteria-infected wound healing. [ABSTRACT FROM AUTHOR]

[Display omitted] • Preparation of graphdiyne by ball milling. • Graphdiyne acetylene with excellent conductivity is beneficial for charge transfer. • The photocatalytic mechanism was further validated through DFT calculations. • The mechanism of double S-scheme heterojunction was explained by in situ characterization. • Excellent hydrogen production performance. In the field of photocatalysis, the inherent properties of catalysts are a hard condition that affects catalytic performance, and constructing heterojunctions is a common method to improve catalyst defects and enhance catalyst performance. This article makes effective use of the outstanding stability and unique electronic structure of graphdiyne, along with its excellent semiconductor properties comparable to silicon. It uses these properties to attach rod-shaped CdS and microspherical NiWO 4 onto sheet-like graphdiyne, creating an S-scheme heterojunction. With the construction of S-scheme heterojunctions and the special contact methods between the three, the physical potential barrier and the distance of electron transfer are reduced. Furthermore, the combined impact of NiWO 4 and graphdiyne works to inhibit the photo corrosion of CdS, enhance its electron transfer capabilities, decrease electron-hole recombination efficiency, and boost hydrogen evolution sites. This maximizes the redox potential during catalysis, leading to exceptional stability and efficiency of the composite catalyst. This study opens up a new avenue for leveraging the superior properties of graphdiyne and advancing sustainable practices. [ABSTRACT FROM AUTHOR]

We utilized the functionalization of N-CDs to systematically modulate the structure and electron transfer behavior of FeNbO 4 catalysts for enhanced CO 2 conversion selectivity to CH 4 in an aqueous solution without any sacrificial agent. This approach shows promise in creating an efficient photocatalyst for the reduction of CO 2 , allowing for tunable CH 4 product selectivity. [Display omitted] • Synthesis of N-doped carbon dots/FeNbO 4 photocatalyst using microwave-assisted hydrothermal method. • Increased lattice strain and oxygen vacancies enhance the CO 2 adsorption on N-CDs/FeNbO 4 photocatalyst's surface. • Accelerated interfacial charge transfer resulting from the introduction of N-CDs promotes charge separation and transfer. • Photocatalytic conversion of CO 2 to CH 4 with high activity and selectivity is achieved. The photocatalytic carbon dioxide reduction reaction (CO 2 RR) is an innovative and reliable technology to address the issues of energy shortage and climate change simultaneously. However, issues such as insufficient light absorption, rapid electron-hole recombination and low surface activity during CO 2 RR severely limit the catalysts' efficiency for photocatalysis. In this study, we present nanohybrid N-CDs/FeNbO 4 catalysts to overcome these challenges and achieve high-efficient photocatalytic conversion of CO 2 to CH 4. The enhancement process starts with the introduction of modified N-CDs, which have a broad light absorption capability. These N-CDs also help to modulate the interfacial charge transfer kinetics, leading to improved charge separation and transfer. This, in turn, enhances the multielectron transfer conversion selectivity of CO 2 to CH 4. Meanwhile, CO 2 adsorption on the photocatalysts is increased due to the creation of oxygen vacancies and lattice stresses resulting from the introduction of N-CDs. This work presents a new approach for improving the photocatalytic performance by adjusting surface structure and interfacial behaviors. [ABSTRACT FROM AUTHOR]

[Display omitted] • The hollow double-shell structure was prepared using tannic acid as a protecting agent. • Ti4+/Ti3+ double-cycling mechanism was proposed. • The domain-limiting effect of the hollow structure promotes photocatalytic hydrogen production. • TiO 2 @NM/Ni 10% exhibits efficient hydrogen production efficiency up to 1659.9 μmol h−1 g−1. Due to their high porosity and structural tunability, MOFs are widely used in photocatalytic hydrogen production. However, unmodified MOFs often suffer from rapid recombination of photogenerated electron-hole pairs. It is a good strategy to construct heterostructures by coupling them with other semiconductor materials. In this paper, hollow double-shell heterostructures TiO 2 @NM/Ni 10% were prepared in situ using tannic acid as a protecting agent. The hydrogen production efficiency of the sample etched for 20 min was as high as 1659.9 μmol h−1 g−1, which was attributed to the formation of Ti4+/Ti3+ double-cycled electron transfer channels between NM/Ni 10% and TiO 2 and the strong built-in electric field established by the type-II heterojunction accelerated the photogenerated carrier separation and transport, which greatly improved the photocatalytic hydrogen production efficiency. In addition, the domain-limiting effect of the hollow double-shell structure enables water molecules to form strong interactions with TiO 2 , providing abundant reaction sites for the catalytic reaction. This structure extends the optical path and enhances light absorption. In this study, a strategy to promote photogenerated carrier separation in MOFs materials by constructing heterojunctions through in situ hydrolysis is proposed, which provides insights for the preparation of efficient hydrogen-producing MOFs photocatalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • Preparation of graphdiyne by ball milling. • Graphdiyne acetylene with excellent conductivity is beneficial for charge transfer. • The photocatalytic mechanism was further validated through DFT calculations. • The mechanism of double S-scheme heterojunction was explained by in situ characterization. • Excellent hydrogen production performance. In the field of photocatalysis, the inherent properties of catalysts are a hard condition that affects catalytic performance, and constructing heterojunctions is a common method to improve catalyst defects and enhance catalyst performance. This article makes effective use of the outstanding stability and unique electronic structure of graphdiyne, along with its excellent semiconductor properties comparable to silicon. It uses these properties to attach rod-shaped CdS and microspherical NiWO 4 onto sheet-like graphdiyne, creating an S-scheme heterojunction. With the construction of S-scheme heterojunctions and the special contact methods between the three, the physical potential barrier and the distance of electron transfer are reduced. Furthermore, the combined impact of NiWO 4 and graphdiyne works to inhibit the photo corrosion of CdS, enhance its electron transfer capabilities, decrease electron-hole recombination efficiency, and boost hydrogen evolution sites. This maximizes the redox potential during catalysis, leading to exceptional stability and efficiency of the composite catalyst. This study opens up a new avenue for leveraging the superior properties of graphdiyne and advancing sustainable practices. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cd 0.9 Zn 0.1 S/CoB heterojunction was constructed by multi-step method. • The CZS/CoB exhibited excellent magnetic separation property. • The photocatalytic H 2 evolution rate reached 59.1 mmol g-1h−1. • The mechanism of Schottky junction and photothermal effect was proposed. The construction of heterojunctions effectively suppresses the undesired recombination of photogenerated charge carriers. This work presents the rational design and preparation of a novel Cd 0.9 Zn 0.1 S/CoB (CZS/CoB) Schottky heterojunction tailored for photothermal-assisted photocatalytic hydrogen evolution with the aid of the predictions of density functional theory (DFT). Under visible light irradiation, the hydrogen evolution rate of CZS/CoB reaches 2.56 times that of pure CZS, due to the formed Schottky heterojunction and photothermal properties, effectively inhibiting electron-hole recombination and boosting the photocatalytic reaction. Notably, with the help of the excellent magnetic properties of CoB, the as-synthesized CZS/CoB exhibits excellent magnetic separation property, which is crucial for practical application. The charge transfer pathways in the Schottky heterojunction were confirmed by experimental results and verified by DFT calculation results. This study presents a feasible strategy for the design and preparation of magnetic recyclable Schottky Heterojunction photocatalyst for photocatalytic hydrogen evolution. [ABSTRACT FROM AUTHOR]

[Display omitted] • Regulating the types of doped metals was found to have both positive and negative effects on the performance of photocatalytic hydrogen evolution. • Cu-doped InP-based QDs show enhanced hydrogen production thanks to the additional energy level introduced for hole capture. • Mn-doped InP-based QDs exhibit poor performance due to Mn4+ reduction during reaction. • A ZnSeS intermediate shell reduces interface defects in InP/ZnS QDs, enhancing photocatalytic performance. Photocatalytic water splitting for hydrogen production has garnered considerable attention as an effective method to alleviate energy shortages. In comparison to cadmium-based quantum dots (QDs) photocatalysts, InP QDs possess a smaller bandgap, larger exciton radius, broader absorption range, and are environmentally friendly. Although InP/ZnS core/shell QDs exhibit immense potential in photocatalysis, they suffer from rapid electron-hole recombination owing to interface defects and lattice mismatch. To address these issues, this study introduces an intermediate ZnSeS shell to reduce defects and tailor QD redox properties through transition metals (manganese and copper) doping. The characterization of QDs was performed from various perspectives, including morphology, element distribution, band structure, and charge transport efficiency. Notably, the photoelectrochemical properties of doped QDs were superior to those of the undoped QDs, while Mn-doped QDs showed inferior catalytic performance compared to the undoped ones. The mechanism of different photoelectrochemical and photocatalytic performances has been studied more intensely. The Mn-doped QDs undergo a process where Mn4+ is converted to Mn2+, consuming electrons in competition with the photocatalytic hydrogen evolution process. Conversely, InP/ZnSeS:Cu/ZnS QDs introduced an additional energy level into the original band structure, capturing some holes and slowing down the electron-hole recombination, thereby providing positive feedback for photocatalytic hydrogen production. Profiting from both the synergies of energy level structure and doping metal state, effective electron-hole separation, and rapid electron transfer to the surface of Cu-doped QDs accomplish the efficient hydrogen generation. The present study offers more possibilities for exploiting the required photocatalytic performance of QD catalysts via elemental doping. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel DAMP and GLU modified CN catalyst for photocatalytic H 2 O 2 production. • High H 2 O 2 production rate of 284.0 μmol g−1h−1 is achieved in pure water. • Two-step single-electron ORR with rapid conversion of •O 2 −. Photocatalytic H 2 O 2 production by g-C 3 N 4 (CN) has drawn intense research attention in the past decade. However, it suffers from drawbacks of weak light absorption capacity and rapid recombination of photogenerated electron-hole pairs. Here, we report a 4, 6-diamino-2-mercaptomidine (DAMP) and glucose (GLU) polymer modified CN (CN-DAMP-GLU) to enhance the photocatalytic performance of CN. The reported modified CN shows a high H 2 O 2 production rate of 284.0 μmol g−1h−1 in pure water, surpassing most of the reported modified g-C 3 N 4 catalysts. The mechanistic study confirms that the rapid conversion of •O 2 − is the key step in the visible-light-driven 2e− oxygen reduction reaction. This step favors efficient H 2 O 2 generation and ensures the stable photocatalytic performance of the system. Experimental and DFT results further reveal that the donor-mediator-acceptor structure (polyfuran-DAMP-CN) with DAMP as the electron transfer mediator can inhibit the electron-hole recombination. We also demonstrate that this photocatalytic H 2 O 2 production system can effectively degrade ciprofloxacin (CIP) through Fenton reaction. This work will promote the development of g-C 3 N 4 for efficient photocatalytic production of H 2 O 2 and possible applications in organic pollutant removal. [ABSTRACT FROM AUTHOR]

• Bamboo-based photocatalyst was prepared by loaded ZnO/WO 3 into bamboo cellulose channels. • The ZnO/WO 3 @bamboo had the effective function of photocatalytic degradation of formaldehyde gas and organic dyes. • ZnO/WO 3 @bamboo demonstrated superior recycling ability. • The decreased of electron hole recombination improved the photocatalytic performance of ZnO/WO 3 @bamboo. A high-performance photocatalyst with both efficient and reusable performance is essentially demanded for the purification of organic wastewater and the removal of indoor formaldehyde. However, recovery of photocatalyst particles from the reaction system remains a challenge. Herein, based on the abundant pore structure of natural bamboo and the outstanding photocatalytic activity of ZnO/WO 3 , we fabricated an efficient bamboo-based photocatalyst (ZnO/WO 3 @bamboo) for the efficient photocatalytic degradation of formaldehyde and organic dyes. The pretreatment of bamboo substrates with NaOH solution resulted in the formation of nucleation sites for ZnO/WO 3 growth within bamboo cellulose channels. Subsequently, the as-prepared ZnO and WO 3 were mixed in different mass ratios, and loaded on the pretreated bamboo substrates using the hydrothermal method. The results showed that the ZnO/WO 3 @bamboo had the effective function of photocatalytic degradation of formaldehyde gas and organic dyes. Moreover, the as-prepared ZnO/WO 3 @bamboo photocatalyst demonstrated superior recycling ability toward organic pollutants, which was described by photocatalytic degradation efficiency of formaldehyde gas more than 89% after 10 cycles, and organic dyes over 93% after 20 cycles. The coupling of ZnO and WO 3 leads to electron delocalization, which caused the electron holes generated in the valence band (VB) of ZnO to delocalize to the VB of WO 3 , and reduced the recombination of electron-hole. Therefore, the photocatalytic degradation performance of the ZnO/WO 3 @bamboo was enhanced. The proposed ZnO/WO 3 @bamboo photocatalyst holds great promise in the field of air pollution and wastewater remediation. [ABSTRACT FROM AUTHOR]

A defective-enriched S-scheme heterojunction of K 3 PW 12 O 40 @WS 2 -Vs (KPW@WS 2 -Vs) with hollow structure was synthesized and utilized for the simultaneous removal of tetracycline (TC) and hexavalent uranium (U(VI)) in wastewater. Density functional theory (DFT) calculations confirmed the unique S-scheme electron transfer mechanism in KPW@WS 2 -Vs heterojunction, which significantly accelerates the separation and transmission of electron-hole pairs with the assistance of S vacancies. Systematic experimental results demonstrated that TC and U(VI) can further serve as the hole and electron scavengers in the co-existence system, leading to a significant synergistic enhancement effect, thereby achieving high simultaneous removal efficiencies of 98.1 % for TC and 95.6 % for U(VI). [Display omitted] • A vacancy-enriched S-scheme heterojunction with a hollow dodecahedral structure is prepared. • The presence of S vacancies in WS 2 regulates the band structure. • The experiments and DFT calculations support the electron transfer mechanism. • The heterojunction exhibits the enhanced capability of synergistically removing pollutants. • The degradation mechanism and pathway of pollutants are proposed. In aquatic environments, the coexistence and interaction of multiple the pollutants complicate remediation process. This study focuses on developing a defective-enriched S-scheme heterojunction of K 3 PW 12 O 40 @WS 2 (KPW@WS 2) with hollow structure for the simultaneous removal of tetracycline (TC) and hexavalent uranium (U(VI)) in wastewater. The internal electric field (IEF) within this heterojunction plays a crucial role in efficiently separating photo-generated carriers, creating high reduction and oxidation active sites. The band structure and optical properties suggest that WS 2 -Vs have a narrower band gap energy compared to conventional WS 2 , leading to improved charge carrier separation and transfer rates. Density functional theory (DFT) calculations support the reduced recombination of electron-hole pairs in WS 2 -Vs due to the presence of S vacancies. Experimental results reveal a synergistic effect between the removal of TC and U(VI), with a significant increase in the reaction rate constant for the reduction of U(VI) to 0.0426 min−1, 1.6 times higher than in a single U(VI) reduction system. Additionally, the reaction rate constant for the oxidation of TC also rises from 0.0573 to 0.0729 min−1. The study also delves into the photocatalytic mechanism, degradation pathways, and intermediate products. Overall, this research offers an innovative strategy for simultaneous pollutant removal and optimizing photocatalytic redox reactions to enhance solar energy utilization. [ABSTRACT FROM AUTHOR]

A novel design strategy of donor–acceptor-catalyst configuration is proposed for CTFs, wherein the photoexcited electrons undergo stepwise transfer from the donor unit to the acceptor unit and ultimately reach the catalytic center. This process effectively suppresses electron-hole recombination. Additionally, the built-in catalytic unit enhances both catalytic activity and product selectivity. [Display omitted] • A novel design strategy of donor–acceptor-catalyst configuration is proposed for CTF photocatalyst. • It enables the stepwise transfer of photoexcited electron, inhibiting electron-hole recombination. • CTF-TT-Ir exhibits a superior HCOOH production rate with an excellent selectivity. • The photocatalytic CO 2 reduction process was investigated via DRIFTS. • To elucidate the selectivity towards HCOOH, the transformation pathway was investigated through DFT calculations. Covalent triazine frameworks (CTFs) have great potential for photocatalysis. However, the electron-hole recombination and the lack of efficient catalytic sites constrain the activity and selectivity. Herein, a novel design strategy of donor–acceptor-catalyst (D-A-C) configuration is proposed. This configuration enables the photoexcited electron undergoes stepwise transfer from donor unit to acceptor unit and ultimately reaches catalytic center, effectively inhibiting electron-hole recombination. The proof-of-concept model CTF-TT-Ir, in which thieno[3,2-b]thiophene (TT) serves as the donor unit, triazine as the acceptor unit, and Cp*Ir(bpy) (Ir) as the built-in catalytic site, was prepared for the photocatalytic reduction of CO 2 to HCOOH. The stepwise transfer of photoexcited electrons in the ternary structure has been demonstrated through the in-situ XPS measurements and the theoretical calculations. Photoluminescence and photocurrent tests have indicated CTF-TT-Ir exhibits superior charge separation efficiency. Without additional photosensitizer and co-catalyst, the photocatalytic HCOOH yield rate of CTF-TT-Ir reached 245 μmol g−1h−1 (selectivity of 97 %). [ABSTRACT FROM AUTHOR]

[Display omitted] • "Edge in-situ heterogeneous" BiOI was synthesized. • BB exhibited the structures of both iodine defects and in-situ bismuth deposition. • The visible-light utilization and charge separation efficiency of BiOI were enhanced. • BB displayed excellent bactericidal ability and wound healing performance. The inherent narrow band gap of bismuth oxyiodide (BiOI) consistently leads to the rapid recombination of photogenerated carriers, significantly constraining its practical utility. To combat this shortcoming, we devise a Bi/BiOI 1−x (BB) nanosheet with edge heterostructure. It is modified by the introduction of both iodine defects and in-situ bismuth deposition through high-temperature calcination and solvothermal strategy. Notably, the in-situ deposition of bismuth enhances the visible-light absorption ability of BiOI. And the incorporation of iodine defects initiates a modification in the band position of BiOI, ultimately diminishing the electron-hole recombination rate effectively. More importantly, facilitated by the major work function of bismuth, a Schottky barrier is formed at the BB heterojunction interface, which effectively promotes the separation of photogenerated charges within BB. And the photocurrent intensity of BB is 4 times higher than that of pure BiOI. These ingenious designs result in a significant boost in the generation of reactive oxygen species (ROS) through the accumulation of electrons and holes on the surfaces of both Bi and BiOI 1−x. And BB photocatalyst shows an outstanding broad-spectrum bactericidal performance. The antibacterial rates against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) are 88.01% and 90.01%, respectively, which are increased by 80.6% and 83.8% compared with BiOI. Moreover, in vivo experiments provide compelling evidence for the BB photocatalyst's potential in promoting wound healing. The healing rate after BB treatment has already reached more than 95% on the fifth day. This work offers valuable insights on enhancing the sterilization performance of photocatalysts based on the synergistic effects of defect engineering and non-noble metal deposition. [ABSTRACT FROM AUTHOR]

• This review incorporates the breakthroughs in biomedical applications of TiO 2-x related nanomaterials. • It conducts a comprehensive comparative analysis of the advantages and disadvantages of TiO 2-x related nanomaterials. • This review provides a new perspective on TiO 2-x related nanomaterials for future medical strategies. Titanium dioxide (TiO 2) is a crucial semiconductor material that is inexpensive, highly stable, and exhibits robust photocatalytic capabilities. Due to these properties, TiO 2 has been widely researched and applied in various scientific and technological fields, such as nanomedicine, hydrogen production, and solar cell technology. However, the practical applications of TiO 2 are limited due to several factors, such as the wide bandgap of TiO 2 and the rapid recombination of electron-hole pairs; in addition, the photocatalytic efficiency must be improved and concerns about the harmful effects of ultraviolet (UV) excitation on the human body must be addressed. To overcome these challenges, researchers have recently employed innovative strategies, such as the removal of oxygen atoms or the introduction of hydrogen, to successfully synthesize reducible titanium dioxide (TiO 2-x). These approaches have altered the crystal structure and chemical properties of TiO 2. The modifications in the optical properties significantly expanded the absorption range of TiO 2-x and achieved efficient electron-hole pair separation, thereby enhancing its operational efficiency. Additionally, changes in the chemical properties of TiO 2 have broadened its application domains. Recently, TiO 2-x nanomaterials have demonstrated vast potential applications, such as enhanced photodynamic antibacterial therapy, photothermal therapy for cancer, and tissue regeneration for tissue defect repair, in various fields, particularly in the biomedical domain. These strategies have addressed the limitations of traditional treatment approaches and have achieved improved therapeutic outcomes. However, a thorough analysis of the use of TiO 2-x in this field is currently lacking, and knowledge within the academic community regarding the breakthroughs, advancements, and new functionalities of TiO 2-x remains relatively limited. Therefore, the primary focus of this paper is to explore the preparation methods and functional properties of TiO 2-x nanomaterials. In particular, their applications and research advancements in the biomedical field are emphasized. Furthermore, a detailed summary and discussion of the opportunities and potential challenges of TiO 2-x nanosystems in future biomedical applications are also presented. In summary, based on their tuneable properties, TiO 2-x nanosystems hold significant potential in the field of biomedicine. With further research and technological innovation, we believe that this nanomaterial will contribute to revolutionary innovations and advancements in the field of biomedicine. [ABSTRACT FROM AUTHOR]

[Display omitted] • Main mechanisms of photocatalytic H 2 O 2 generation are summarized. • Merits and demerits of various strategies on improving H 2 O 2 production are analyzed. • Application of photocatalytic H 2 O 2 evolution in environmental remediation is studied. • Challenges and perspectives facing photocatalytic H 2 O 2 generation are proposed. As a renewable energy carrier and an environmental-friendly oxidant, hydrogen peroxide (H 2 O 2) has attracted widely attention. In comparison with conventional anthraquinone process, photocatalytic H 2 O 2 generation is a sustainable, simple, safe, and green process, so there is a growing body of research on photocatalytic H 2 O 2 generation. In this review, the progress and challenge of photocatalytic H 2 O 2 generation are summarized, including the main mechanism of photocatalytic H 2 O 2 synthesis, and design and modification principles of photocatalyst. Notably, the main issues facing photocatalytic H 2 O 2 synthesis are low utilization of solar energy, high recombination rate of electron-hole pairs, poor selectivity of product, and easy decomposition of H 2 O 2. To overcome these problems, various effective and feasible strategies are proposed, and the mechanisms, advantages and disadvantages of these strategies are also discussed. Furthermore, the environmental applications of photocatalytic H 2 O 2 evolution are summarized in brief. More significantly, the challenges and future prospects about photocatalytic H 2 O 2 production are proposed. In short, it is expected that this review can share some meaningful insights into photocatalytic H 2 O 2 generation and provide some valuable references for future research. [ABSTRACT FROM AUTHOR]

The formation of ultra-low resistance interface by the Ohmic contact (Pd nanocubes/In 2 O 3) and the built-in electric field enhanced by the metal–carbon (Pd nanocubes/HMC) interaction significantly inhibits the recombination of electron-hole pairs, facilitates the migration of charge carriers, and greatly enhances photoredcution activity of CO 2 -to-CO. [Display omitted] • An Ohmic contact-structured Pd/In 2 O 3 /C (PIC) photocatalyst is designed with an ultra-low interfacial resistance. • The enhanced built-in electric field in PIC significantly accelerates photogenerated charge transfer. • The PIC achieves a high CO yield of 99.4 μmol∙g−1∙h−1 under full spectrum irradiation. The utilization of CO 2 photoreduction into valuable hydrocarbon fuels presents a promising avenue for mitigating climate change and providing a sustainable energy source. However, photogenerated carriers are highly prone to recombination, which adversely affects photocatalytic activity. In our study, we introduce a novel photocatalyst synthesis method, featuring an Ohmic contact (OC) structure that incorporates biomass-derived hollow carbon microspheres (HCM), Pd nanocubes (NC), and Indium Oxide (In 2 O 3) through a simple yet effective thermal reduction method. This modification significantly enhances the photocatalytic efficiency of the Pd NC/In 2 O 3 /HCM (donated as PIC) system, achieving an optimal value of 496.89 μmol∙g−1 over 5 h without the need for additional additives, 8.7-fold higher than that of the pristine In 2 O 3. Experimental and theoretical results reveal that the substantial enhancement in CO 2 photoreduction performance can be attributed to the ultra-low resistance (122 Ω) interfaces within the PIC system, facilitating accelerated transfer of photogenerated electrons. This work provides a strategy for boosting CO 2 photoreduction efficiency by the reduction of interface resistance to promote rapid photogenerated electron migration. [ABSTRACT FROM AUTHOR]

• First in-situ X-ray absorption experiment reveals the key role of Co-Ci for solar water splitting. • Co can obtain electrons during illumination while Fe can get holes to form high-valence Fe4+. • Co-Ci leads to suppressed charge recombination and increased oxidation capability. • The photoanode can finally achieve a high photocurrent of 4.10 mA/cm2 (1.23 V RHE). Surface co-catalyst has been widely used to improve the performance of hematite for solar water splitting. However, the specific working mechanism for co-catalyst has not yet been extensively studied, especially lacking for in-situ information. Here we report a Co-Ci/Zr-Fe 2 O 3 (LV) photoanode for efficient water splitting and probe the working mechanism of surface Co-Ci by in-situ X-ray absorption spectroscopy (XAS) under illumination. The low vacuum treatment and the Zr-doping in Co-Ci/Zr-Fe 2 O 3 (LV) can significantly increase the donor density and then facilitate the bulk charge transfer, while the surface Co-Ci co-catalyst can greatly reduce the electron-hole recombination and then lower the onset potential. In-situ XAS reveals that under illumination, the photon-excited electrons will be quickly transferred to the Co sites in Co-Ci, while the excited holes will be left on Fe to form the high-valence Fe4+ to enhance the oxidation capability. As a result, the combined Co-Ci/Zr-Fe 2 O 3 (LV) photoanode shows a quick bulk charge transfer and a low surface charge recombination, leading to a high photocurrent density of 4.10 mA/cm2 (1.23 V RHE) and a low onset potential of 0.85 V RHE with good stability. [ABSTRACT FROM AUTHOR]

[Display omitted] • D-A structure and K gradient were introduced into PCN via KCl-assisted calcination. • D-A structure and K gradient synergistically promoted the oriented charge transfer. • The PHE performance of TCN-K-10 was 17.9 times higher than that of BCN. Polymeric carbon nitride (PCN) is regarded as a most promising photocatalyst, but the severe recombination of electron-hole pairs restrains its photocatalytic performance. Herein, a carbon nitride gradient homojunction with donor–acceptor (D-A) structure was successfully synthesized. The D-A structure promoted the electron delocalization, while gradient K intercalation helped establish a strong internal electric field from the interior to the surface. They synergistically inhibited the recombination of electron-hole pairs and led to fast charge transfer and much enhanced photocatalytic hydrogen evolution (PHE) performance. This work developed a novel method to promote the charge carrier transfer in carbon nitrides, which could provide a new perspective for the design and development of carbon nitride-based homojunctions in the application of PHE. [ABSTRACT FROM AUTHOR]

• The removal efficiency of the Co-doped BiOIO 3 photocatalyst reached up to 91.0% under visible light. • The effect of oxygen vacancies on the photocatalytic activity of Co/BiOIO 3 photocatalysts was investigated. • The mechanism of Hg0 oxidation by Co/BiOIO 3 was proposed. BiOIO 3 has a broad prospect in photocatalytic oxidation, but during photochemical process, the overall efficiency of photocatalysis is not satisfactory due to the short carrier lifetime and the easy recombination of electron-hole pairs. To address these issues, Co2+-doped BiOIO 3 photocatalysts were successfully prepared using a hydrothermal method by induce oxygen vacancies to enhanced photocatalytic activity of the photocatalysts. The prepared catalysts are not only cost-effective, but also simple in the preparation process and have long-lasting stability while maintaining high photocatalytic activity. The Co-doped BiOIO 3 photocatalysts exhibited high photocatalytic mercury removal efficiencies of up to 91.0 % in the photocatalytic removal experiments of gaseous mercury. The optimal doping ratio sample could still reach 83. 58 % after a 660 min long-term photocatalytic experiment, which proves that the Co ion-doped BiOIO 3 photocatalyst has good stability. The energy band structure of Co-doped photocatalysts was analyzed based on density-functional theory (DFT), and the mechanism of photocatalyst activity enhancement by Co-doping was proposed in conjunction with experimental and characterization. The findings of this research provide a valuable reference for future investigations on the coupling of transition metal ions with photocatalysts, and establishes a strong foundation for multivariate coupling or bimetallic ion doping of the three, and offers a realistic technological path for the creation of highly stable and effective photocatalysts used to remediate air pollution. [ABSTRACT FROM AUTHOR]

• Z-scheme ZIS/BTO heterojunction with piezoelectric effect was synthesized. • ZIS/BTO heterojunction promoted charge separation and prolonged carrier lifetime. • Charge transfer mechanism was investigated by DFT calculations and experiments. • ZIS/BTO heterojunction exhibited significant CO yield under light and ultrasound. Converting CO 2 into high-value-added chemicals by artificial photosynthesis technology effectively solves environmental problems and energy shortages. Nevertheless, it remains challenging to improve CO 2 conversion rates due to low photo-utilization and rapid electron-hole recombination. In this study, we successfully synthesized direct Z-scheme ZnIn 2 S 4 /BaTiO 3 heterojunction structure by a hydrothermal method. Specifically, compared with previous studies of various heterojunction catalysts, ZnIn 2 S 4 /BaTiO 3 heterojunction structure achieved a remarkably high yield of 105.89 μmol g-1 h-1, increasing 2.55 and 3.62-fold over the individual performance of ZnIn 2 S 4 and BaTiO 3 , respectively. Our investigation of photocatalytic mechanism suggest that the improved photocatalytic CO 2 reduction performance can be attributed to the synergistic effects of the piezoelectric effect and Z-scheme electron transfer mechanism. These effects can synergistically enhance space charge separation and retain photogenerated electrons, thereby facilitating a more efficient CO 2 reduction process. Consequently, this innovative piezoelectric effect-assisted Z-scheme heterojunction demonstrates immense potential to offer a novel strategy for addressing CO 2 reduction challenges and advancing sustainable energy development. [ABSTRACT FROM AUTHOR]

[Display omitted] • The changes in the valence states of Fe and Co within the cocatalyst FeCo 2 O 4 facilitate the water oxidation reaction. • The MgO interlayer effectively inhibits the recombination of photogenerated carriers. • The reaction kinetics are enhanced by the super-hydrophilic nature of the photoanode surface. To address the issue of inefficient charge transfer efficiency at the semiconductor/cocatalyst interface, we engineered a BiVO 4 /MgO/FeCo 2 O 4 array, incorporating a MgO interlayer. This design aimed to enhance the performance of photoelectrochemical (PEC) water splitting on BiVO 4 and FeCo 2 O 4. The introduced interlayer efficiently hinders hole backflow, promoting unimpeded charge migration within the multi-hybrid structure. This, in turn, significantly reduces the recombination of electron-hole pairs. In addition, the BiVO 4 /MgO/FeCo 2 O 4 undergoes a low-temperature plasma treatment, resulting in super-hydrophilicity. This treatment enhances charge migration efficiency and fosters extensive contact between the electrolyte and electrode interfaces. Photoelectrochemical analysis demonstrates that H-BiVO 4 /MgO/FeCo 2 O 4 exhibits exceptional performance for the oxygen evolution reaction (OER), showcasing a photocurrent density of 4.3 mA·cm−2 at 1.23 V vs. RHE in 0.5 M Na 2 SO 4 under AM 1.5 G (100 mW·cm−2) illumination. Remarkably, this value is 5.2 times higher than that observed for BiVO 4. Furthermore, the maximum incident photon to current conversion efficiency (IPCE) reaches an impressive 61.7 %, surpassing that of BiVO 4 and BiVO 4 /FeCo 2 O 4 by approximately 5.1 and 1.7 times, respectively. Additionally, the charge separation efficiency of H-BiVO 4 /MgO/FeCo 2 O 4 achieves a notable 83.4 %, and the charge injection efficiency is substantially improved. This study advocates for a straightforward yet highly effective approach to mitigate interfacial electron-hole recombination. [ABSTRACT FROM AUTHOR]

[Display omitted] • Z-shceme photocatalyst was prepared by milling based on electrostatic attraction. • Persulfate activation and photocatalysis for sulfamethoxazole degradation. • Radicals (h+, O 2 •-, SO 4 •-, and •OH) and non-radical (1O 2) were detected. • The degradation mechanism of sulfamethoxazole degradation was investigated. • Degradation routes of sulfamethoxazole and toxicity simulation. Recently, the removal of antibiotics from wastewater has become increasingly important. Advanced oxidation processes (AOPs) combining persulfate (PS) activation and photocatalysis have been proven as a promising strategy for antibiotics degradation. For the first time, the β-alanine modified perylene diimide derivative (β-PDI) and MIL-101(Fe) were selected to create novel Z-scheme photocatalysts (MP x) by simple milling method based on the electrostatic attraction. The optimal MP 50 /PS/vis system could remove 99.7 % of SMX within 6 min and the MP 50 displayed great recyclability and sustainability. The persulfate as electron scavenger not only inhibited the recombination of photogenerated electron-hole pairs but also generated additional SO 4 •-, thereby improving the efficiency of SMX degradation. The removal of SMX was simultaneously dependent on radicals (h+, O 2 •-, SO 4 •-, and •OH) and non-radical (1O 2) pathways, and it is noteworthy that h+ played a major role. LC-MS was applied to investigate the degradation pathways and intermediates of SMX, their toxicities were further studied and the results showed that the MP 50 /PS/vis system was successful in reducing its biotoxicity and the risk of inducing potentially drug-resistant bacteria. This work provided profound insights into the mechanism of antibiotic degradation by persulfate activating-photocatalysis coupling AOPs. [ABSTRACT FROM AUTHOR]

• Biodegradable CoSnO 3 nanocubes are employed as sonosensitizers and nanozymes. • GQD/CoSnO 3 is constructed by depositing GQD topoisomerases inhibitors on CoSnO 3. • Heterojunction-fabricated GQD/CoSnO 3 shows cascaded amplification of ROS generation. • Tumor-specific release of GQDs for chemotherapy is realized after completion of SDT. • GQD/CoSnO 3 achieves complete tumor eradication through chemotherapy, SDT, and NCT. Albeit nanozymes are widely applied for nanocatalytic therapy (NCT), the unsatisfactory catalytic activity of nanozymes accompanied by complex tumor microenvironment (TME) greatly pose a barrier to the therapeutic effect of NCT. Moreover, developing a high-efficiency nanozyme with biodegradability is still a huge challenge, which hinders their further clinical translation. Herein, pH-responsive biodegradable CoSnO 3 nanocubes are synthesized and employed as sonosensitizers and nanozymes due to their narrow bandgaps (1.6 eV) and Co2+/Sn4+-mediated multi-enzyme activities. After depositing the graphene quantum dot (GQD) topoisomerase inhibitors on CoSnO 3 nanocubes, the heterojunction-fabricated GQD/CoSnO 3 shows cascaded amplification of ROS generation, which is ascribed to the inhibition of electron-hole pair recombination, Co2+-mediated peroxidase (POD)-mimic catalytic reaction to generate OH, Co3+/Sn4+-mediated depletion of overexpressed GSH, and catalytic decomposition of endogenous H 2 O 2 for providing more O 2 for enhanced SDT. More importantly, GQD/CoSnO 3 heterojunctions are slowly degraded in the weakly acidic TME, resulting the tumor-specific release of GQDs after completion of SDT, which could induce DNA damage and cell apoptosis for chemotherapy to further enhanced the antitumor efficacy. The synergetic therapeutic efficacy of GQD/CoSnO 3 heterojunctions through chemotherapy, SDT, and NCT could realize "three-in-one" multimodal oncotherapy to completely eliminate tumors without recurrence. This work provides a paradigm of exploring pH-responsive biodegradable nanozymes as a drug carrier to realize tumor-specific drug release for enhanced SDT and NCT. [ABSTRACT FROM AUTHOR]

• A coprecipitation method was applied to fabricate BiOBr/MIL-53(Fe) novel photocatalyst. • The MIL-53(Fe) doping endowed BiOBr with the stronger adsorption ability and higher utilization efficiency of visible light. • The heterojunction can be formed between MIL-53(Fe) and BiOBr to enhance the photocatalytic degradation performance. • The degradation pathway of carbamazepine was put forward based on the experimental results. In this work, a series of BiOBr/MIL-53(Fe) hybrid photocatalysts have prepared by a facile co-precipitation method. Rhodamine B (RhB) and carbamazepine (CBZ) were selected as the targets to evaluate the visible-light photocatalytic activity of the prepared samples. All of the hybrids exhibited better catalytic performance compared to the pristine BiOBr, and the performance of BiOBr/MIL-53 (with 20 wt% of MIL-53) was the most efficient. The excellent performance can be contributed to the incorporation of MIL-53(Fe) which not only form the heterojunction with BiOBr to inhibit the recombination of the photoinduced electron-hole pairs, but also utilize the visible light more effectively. The photocatalytic mechanism was studied, it shows that OH and h+ were both the main active species for the degradation of contaminants. Moreover, the degradation pathways of CBZ via the photocatalysis over BiOBr/MIL-53(Fe) hybrid were presented based on the determination of LC–MS/MS and the results of catalytic mechanisms. With the recent increase in reported MOFs materials, we believe a new class of hybrid catalytic materials is possible. This result is conceptually interesting as it opens the door to various MOF-based BiOBr materials for environmental purification and restoration. [ABSTRACT FROM AUTHOR]

• A highly efficient TiO 2 NSs/TCPP hybrid for photoreduction of CO 2 was developed. • The hybrids possessed much enhanced photocatalytic activity compared with TiO 2 NSs. • The TCPP loading has important influence on the efficiency of CO 2 photoreduction. • The efficient interfacial charge migration and separation account for the enhanced activity. The design and construction of photocatalysts in converting CO 2 into value-added chemicals is of significant importance for addressing energy shortages and environmental pollution problems. In this work, a TiO 2 nanosheets/tetra (4-carboxyphenyl) porphyrin (TiO 2 NSs/TCPP) hybrid for photoreduction of CO 2 was developed using a simple self-assemble approach. The TCPP works as the light-harvesting unit to generate light-induced electron-hole pairs, with the connection between the TCPP and TiO 2 facilitating the electron injection to the CB of TiO 2 as well as inhibiting the recombination of photo-generated electron-hole pairs, then the highly active (0 0 1) facets of TiO 2 NSs serve as the reaction sites and efficiently convert the CO 2 molecules adsorbed on the surface of the catalysts into CO and CH 4 products. The influence of TCPP content on the photocatalytic activity was investigated. Compared to the pristine TiO 2 NSs material, the TiO 2 NSs/11.5% TCPP composite displayed a much-enhanced photocatalytic CO 2 reduction activity, which is equal to 37-fold enhancements in the CO evolution rate. Furthermore, a possible mechanism for CO 2 photoreduction over TiO 2 NSs/TCPP hybrids is proposed on the basis of the photocatalytic and photo(electro)chemical results. [ABSTRACT FROM AUTHOR]

The active sites of nitrogen-defected carbon nitride with high efficiency for photocatalytic H 2 production are revealed. • g-C 3 N 4 with abundant N-defects (CNx) is synthesized by the HNO 3 modification. • CNx shows 19 times higher activity than g-C 3 N 4 for photocatalytic H 2 evolution. • CNx has an excellent stability for photocatalytic H 2 evolution. • The surface functional groups and the N defects impact the catalytic efficiency significantly. • The active-site structure diagram of CNx for photocatalysis is revealed. The deficient carbon nitride (g-C 3 N 4) displays not only an improved visible light absorption, but also an enhanced photocurrent and restricted electron-hole pair recombination. In this work, nitric acid was used to engineer the defects in g-C 3 N 4 , which simultaneously possessed fibrous and layered structures. The modified g-C 3 N 4 (CNx) was utilized as photocatalyst for the effective photocatalytic H 2 evolution. As high as 1160 μmol/h/g H 2 production rate (λ > 400 nm) was achieved over CN3, 19 times higher than that of pristine g-C 3 N 4 (CN0, 60 μmol/h/g). The apparent quantum efficiencies (AQE) of CN3 at 405 and 420 nm were 7.83% and 7.67%, respectively. The mechanism study showed that the surface functionality and the N defects impacted the catalytic efficiency significantly. The O C, NH x species and N defects at N 2C site acted as the active sites for the photocatalytic hydrogen evolution, while the OH group displayed the negative effect in this process. To the best of our knowledge, the active-site structure diagram of the nitrogen-defected CNx for photocatalysis was shown systematically. Additionally, this nitrogen-defected CNx demonstrated a high stability for photocatalytic hydrogen evolution. [ABSTRACT FROM AUTHOR]

• A 3D free-standing photo-catalyst Ag NPs/ZnO NAs/NiF was successfully prepared. • The enhanced photo-catalytic performance for degradation of berberine was obtained. • The photo-degradation intermediates of berberine and mechanisms were proposed. • The Ag NPs/ZnO NAs/NiF photo-anode was applied in PFC with effective performance. Berberine is a widely used antibiotic in China, its photocatalytic degradation is not well understood nor its efficient treatment reported. In this study, it is most quickly and efficiently degraded (97.9% under UV and 98.9% under visible light) using a free-standing 3D composite photo-electrode, with well dispersed Ag nanoparticles (Ag NPs) over well-aligned ZnO nanorods arrays (ZnO NAs) on Ni foam (NiF), compared to ZnO NAs/NiF, ZnO powder and P25. The composite photo-electrode was prepared by first directly growing ZnO NAs on NiF hydrothermally, followed by photo-deposition of Ag NPs, without any inactive binders or non-conductive substrates. It was characterized using scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), X-ray Diffraction (XRD), ultraviolet–visible spectrophotometry (UV–Vis) and electrochemical analysis (I-t, EIS). The highest activity of Ag NPs/ZnO NAs/NiF in degrading the target pollutant, is due to the synergy of easy pollutants diffusion and fast reaction on active sites, from suppressed electron-hole recombination by Ag NPs/ZnO NAs heterojunctions, extended light absorption by surface plasmon resonance (SPR) of Ag NPs and accelerated electron transport on the conductive macro-porous NiF. The reactive oxidizing species (OH, O 2 −, h±), degradation intermediates and possible degradation pathways of berberine over Ag NPs/ZnO NAs/NiF were examined respectively. This free-standing whole piece photo-electrode with UV–visible light response, is easy to recycle and assemble, that not only degrades pollutant, but also generates electricity as photo-anode in a photo-catalytic fuel cell reactor using carbon fiber cloth as cathode. [ABSTRACT FROM AUTHOR]

• TiO 2 /Al 2 O 3 can degrade X-3B dye under natural indoor weak light when adsorption. • Al 2 O 3 enhanced adsorption and photocatalytic property of TiO 2 /Al 2 O 3. • Surface hydroxyl played an important role in both adsorption and degradation. • Photodegradation assisted adsorption of X-3B under weak indoor light illumination. It's still a big challenge for TiO 2 nanoparticles to be applied in practice due to its low quantum and limited visible light adsorption ability. Herein, we synthesized TiO 2 /Al 2 O 3 nanocomposite by decorating TiO 2 film on Al 2 O 3 surface via a wet-chemical method. This nanocomposite displayed a core-shell like structure with two-phase hybrid of Al 2 O 3 and TiO 2 , and possessed good adsorption and photocatalytic properties under natural indoor weak light due to synergetic effect of Al 2 O 3 and TiO 2. The maximum adsorption capacity of X-3B on TiO 2 /Al 2 O 3 can attain 416.67 mg/g, and does not be influenced by solution pH until pH value is above 10.0. A reducing band gap energy (Eg = 2.94 eV) indicated Al 2 O 3 in nanocomposite can enhance photocatalytic property by blocking the recombination of electron-hole pairs. Scavenger experiments and ESR spectra illustrated that hydroxyl radical played an important role in degradation of X-3B under natural indoor weak light. XPS analysis indicated that the excellent adsorption and photocatalytic performance were heavily related with surface hydroxyls of TiO 2 /Al 2 O 3. [ABSTRACT FROM AUTHOR]

• A novel ternary heterostructure of carbon plane/g-C 3 N 4 /TiO 2 is fabricated. • Carbon plane/g-C 3 N 4 /TiO 2 can promise effective ternary heterojunction contact. • The ternary heterostructure possesses efficient carrier separation and transfer. • Enhanced visible-light photocatalytic activity is realized by the ternary hybrid. • Carbon plane/g-C 3 N 4 /TiO 2 exhibits excellent stability and reusability. Effective interface contact between components in heterojunction is crucial to realize high photocatalytic performance of photocatalyst. In this paper, the improvement of heterojunction contact by forming new ternary heterostructure via calcining the mixture of tetracycline and melamine to obtain the graphene-like carbon plane grafted g-C 3 N 4 and then coupling it with TiO 2 is reported. The unique carbon plane, which is anchored into g-C 3 N 4 basal domains, acts as a significant role to achieve the sufficient ternary heterojunction contact in the novel carbon plane/g-C 3 N 4 /TiO 2 nanostructure system. Under visible-light irradiation, the new ternary nanocomposite exhibits excellent photocatalytic activity for efficient removal of aqueous organic contaminants: methylene blue (98.6%), tetracycline (94.0%), and norfloxacin (95.3%), with the corresponding degradation rate constants of 0.0441, 0.0302, and 0.0125 min−1, respectively, which are 54.1, 9.8, and 9.4 times higher than that of the pure g-C 3 N 4. The mechanism study indicates that the excellent photocatalytic activity is attributed to the effective heterojunction, which can successfully extend visible-light absorption, promote charge separation efficiency, and suppress recombination of the photocatalytic electron-hole pairs. Moreover, the electron spin resonance (ESR) assay and radical scavenger experiments demonstrate that the photogenerated holes (h+), superoxide anion radicals (O 2 −), and hydroxyl radical (OH) play vital roles in photocatalytic degradation process. Importantly, this work may open up novel insights into the design of ternary heterostructure with highly efficacious photocatalytic performance, which suggests attractive applications in environment protection. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A new approach to synthesize Cu 2 O/Ni(OH) 2 nanocomposite. • Photoconversion efficiency (PCE) is discussed. • PCE of Cu 2 O/Ni(OH) 2 nanocomposite is dominated by the light harvesting and external quantum efficiency. • PCE of the Cu 2 O/Ni(OH) 2 nanocomposite is twice that of the Cu 2 O. • Highest hydrogen production rate of the Cu 2 O/Ni(OH) 2 is 15 times that of the Cu 2 O. Abstract Cu 2 O/Ni(OH) 2 nanocomposites have been evaluated for use as a photocathode in hydrogen production cell. The Cu 2 O/Ni(OH) 2 nanocomposites were synthesized using a facile two-step solution method and green route method at room temperature. Cu 2 O spheres were first prepared, followed by the growth of Ni(OH) 2 on the spheres. Cu 2 O/Ni(OH) 2 nanocomposites having different percentages of Ni(OH) 2 were made. The released Ni from Ni(OH) 2 acts as co-catalysts assisting electron transfer and hence suppressing electron-hole recombination. For comparison, both the Cu 2 O spheres and Cu 2 O/Ni(OH) 2 nanocomposites were characterized and examined as a photocathode in photoelectrochemical cell for hydrogen production. The performance of the photocathode has been discussed in terms of light harvesting efficiency (LHE), external quantum efficiency (EQE), charge collection efficiency (CCE), and photoconversion efficiency (PCE). The LHE and EQE of the Cu 2 O/Ni(OH) 2 nanocomposite is better than that of the Cu 2 O spheres. We show that for the Cu 2 O spheres, PCE increase linearly with the CCE, while for the Cu 2 O/Ni(OH) 2 nanocomposites, the PCE increase and then levels off with the CCE. Furthermore, we have demonstrated the synergistic effect of coupling Cu 2 O/CuO with double co-catalyst Ni(OH) 2 /Ni, which greatly enhances the electron transfer and effectively reduce the hole-electron recombination. As a result, the PCE of the Cu 2 O/Ni(OH) 2 nanocomposite was found to be twice that of the Cu 2 O spheres. Furthermore, the highest hydrogen production rate of the Cu 2 O/Ni(OH) 2 is more than 15 times that of the Cu 2 O. [ABSTRACT FROM AUTHOR]

Graphical abstract The photocatalytic activity of g-C 3 N 4 /Bi 2 O 2 CO 3 for antibiotics degradation was greatly enhanced, which was attributed to the relatively faster charge transfer rate and the deeply suppressed recombination of photo-generated electron-hole pairs through g-C 3 N 4 surface-decoration. Highlights • The charge transfer in g-C 3 N 4 /Bi 2 O 2 CO 3 was clarified by first principle simulation. • g-C 3 N 4 surface-decorated Bi 2 O 2 CO 3 was fabricated via a facile hydrothermal method. • g-C 3 N 4 surface-decorated Bi 2 O 2 CO 3 displayed enhanced photocatalytic activity. • g-C 3 N 4 surface-decoration facilitated charge transfer and separation at the interface. • The photocatalytic activity for TC degradation in actual water was also evaluated. Abstract To overcome the issue of UV-light response character of Bi 2 O 2 CO 3 due to its wide band gap, we primarily attempted to understand the possibility of improving the photocatalytic activity of Bi 2 O 2 CO 3 via g-C 3 N 4 surface-decoration by the theoretical calculation. Subsequently, g-C 3 N 4 surface-decorated Bi 2 O 2 CO 3 was successfully prepared via a facile hydrothermal method. It was found that the g-C 3 N 4 surface-decorated Bi 2 O 2 CO 3 samples exhibited enhanced activities for the photodegradation of tetracycline compared with pure Bi 2 O 2 CO 3 upon simulated solar light irradiation. Among them, the 10 wt% g-C 3 N 4 surface-decorated Bi 2 O 2 CO 3 sample showed the highest photocatalytic efficiency. First principle calculation and experimental data confirmed that the charge transfer at the interface between g-C 3 N 4 and Bi 2 O 2 CO 3 could significantly suppress the recombination of photo-generated electron-holes pairs, thus improving the photocatalytic performance. The proposed mechanism for the enhanced photocatalytic activity was also discussed. Moreover, the photodegradation of antibiotics over g-C 3 N 4 surface-decorated Bi 2 O 2 CO 3 was also performed in actual water matrix. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The trap-level-tunable Se-doped CdS QDs were fabricated for the first time. • Se-doping elevated Fermi level position of CdS, leading to the capture of electrons. • Se-doping promoted the production of more photo-generated electrons and holes. • CdS 0.9 Se 0.1 exhibited the photocatalytic H 2 evolution rate of 29.12 mmol h−1 g−1. • The AQE over CdS 0.9 Se 0.1 reached 27.1% at 400 nm without co-catalyst. Abstract Element doping has been extensively employed to modulate the physicochemical properties of semiconductors. In this work, Se-doped CdS quantum dots (QDs) with varied Se doping level are fabricated via a solvothermal procedure. Due to the introduction of Se, the Fermi level position of CdS is elevated to a higher position, leading to the effective capture of photogenerated electrons by the trapping sites, which greatly inhibits the recombination of electron-hole pairs and thus prolong the charge carriers' lifetime. Furthermore, due to the introduction of Se, the density of charge carriers in CdS is significantly enhanced, which is conducive to the production of more photo-generated electrons and holes. It is because of the two favorable factors that the photocatalytic performance of the resultant CdS 0.9 Se 0.1 QDs is greatly improved with a remarkable hydrogen evolution rate of 29.12 mmol h−1 g−1 under simulated solar irradiation (320–780 nm) without any co-catalysts, which is 23.5 times that of the pristine CdS QDs under the same conditions. Moreover, the apparent quantum efficiency (AQE) over CdS 0.9 Se 0.1 QDs reaches 27.1% at 400 nm without co-catalyst addition. This work confirms the feasibility of suppressing the recombination of electron-hole pairs by adjusting the capture level with impurity doping for exploring highly efficient photocatalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • A crystalline-amorphous TiO 2 /Ce 2 O 3 heterojunction with an average size of 15 nm is constructed for UV-shielding. • The TiO 2 /Ce 2 O 3 exhibits significantly reduced photocatalytic activity. • The heterostructure promotes the recombination of electron-hole pairs and reduces the carriers' redox potential. • OP modification provides OP-TiO 2 /Ce 2 O 3 near-monodispersity and good compatibility with fluorocarbon resin. As a stable and inexpensive UV-absorber, TiO 2 is widely used in UV-shielding products. However, its poor compatibility with matrix polymers and photocatalytic degradation hazard still limit its performance. Herein, we construct the crystalline-amorphous TiO 2 /Ce 2 O 3 heterojunctions with an average size of 15 nm via an in-situ solvothermal process, significantly reducing the photocatalytic activity through the carrier redistribution between TiO 2 and Ce 2 O 3. In the photocatalytic experiments for the degradation of three dyes (RhB, MB, and RR-120), the apparent reaction rate constants (k) of the optimal sample TiO 2 /Ce 2 O 3 -3 % are 33.92, 28.54, and 24.78 times lower than those of pure TiO 2 , respectively. The characterizations and theoretical calculations together reveal that the photogenerated carriers accumulate on the amorphous Ce 2 O 3 with rich defects, promoting the recombination of electron-hole pairs and reducing the carriers' redox potential. Additionally, oleyl phosphate (OP) is used for surface modification to achieve TiO 2 /Ce 2 O 3 organic solvent-dispersible and improve its compatibility with matrix polymers, thus the UV-shielding OP-TiO 2 /Ce 2 O 3 /fluorocarbon hybrid coating is prepared with high transparency. [ABSTRACT FROM AUTHOR]

[Display omitted] • The UV PD was constructed face-to-face from TiO 2 NRs: CQDs/FTO and PEDOS/FTO. • Sensitization of TiO 2 NRs by CQDs enhances the pyro-phototronic effect of TiO 2 NRs. • CQDs and PEDOS interact with each other and have matching energy levels. • The photovoltaic-pyroelectric coupled effect enhanced the performance. • The UV PD have high responsivity and detectivity in the self-powered model. TiO 2 -based ultraviolet (UV) photodetectors (PDs) with broadband optical detection range are widely used in commercial and military applications. Nevertheless, the self-powered UV PDs of TiO 2 nanoarrays (NRs) have relatively low response rates and slow response times. Here, a high responsivity self-powered p-n heterojunction UV PD based on TiO 2 NRs: CQDs/FTO and PEDOS/FTO is fabricated by a simple face-to-face assembly process. The pyroelectric effect of TiO 2 NRs is enhanced by sensitizing TiO 2 NRs with CQDs, which would reduce the bandgap value of TiO 2 NR, broaden the range of photoresponse, and reduce recombination of electron-hole. Furthermore, the pyro-phototronic effect of CQDs, the energy level matching from CQDs to PEDOS and the interaction between –OH in CQDs and ethylene oxide groups in PEDOS enhance the performance of the prepared UV PDs. The TiO 2 NRs: CQDs//PEDOS UV PDs achieve a high photo-responsivity and photo-detectivity of 150.95 mA/W and 3.73 × 1011 Jones at 0 bias (365 nm), respectively, which are better than those at wavelengths of 380 nm. We also found that the photocurrent induced via the pyro-phototronic effect increases with the light power intensity. This work points the way for photovoltaic and photo-induced pyro-phototronic effects to improve the performance of TiO 2 NRs-based UV PDs. [ABSTRACT FROM AUTHOR]

• Novel donor–acceptor (D–A) covalent organic framework (COF), COF-BT was developed. • CoO was incorporated via a two-step impregnation and calcination method. • Co-COF-BT can be highly useful in the artificial photoreduction of CO 2. • Superior catalytic performance attributed to the synergistic effect of D–A and CoO. Artificial photoreduction of CO 2 is considered an attractive solution for simultaneously achieving carbon neutrality goals and solving the energy shortage crisis. In this study, a donor–acceptor (D–A) covalent organic framework (COF), COF-BT, comprising (1,1′-biphenyl)-3,3′,5,5′-tetracarbaldehyde and 4,4′-(2,1,3-benzothiadiazole-4,7-diyl)bis[benzenamine] was prepared, and cheap CoO was introduced into COF-BT via a two-step impregnation-calcination process to obtain Co-COF-BT with immobilized transition metals. Photoelectrochemical experimental and theoretical results indicate that the D–A structure of Co-COF-BT reduces the band gap, enhances visible light absorption, inhibits electron–hole recombination, and prolongs the life of photogenerated carriers. The introduction of CoO provides additional active sites, and the Co-S bond in Co-COF-BT provides an additional channel for ultrafast electron migration from the COF-BT unit to the CoO active center, which increases charge mobility and reduces the energy barrier formed by *COOH intermediates. Thus, the excellent photocatalytic CO 2 reduction activity of Co-COF-BT is achieved with a CO yield of 2423 μmol g−1h−1 and selectivity > 99% under visible light. The superior photocatalytic performance is attributed to the synergistic effect of D–A moieties and CoO in Co-COF-BT. This study not only presents a novel COF-based photocatalyst with high charge transfer efficiency and high catalytic activity in CO 2 reduction but also provides a potential strategy to fine-tune photoelectronic properties by adjusting the functional building blocks and additional metal active sites. [ABSTRACT FROM AUTHOR]

[Display omitted] • The TADF polymers were synthesized as semiconductor additives for perovskite LEDs. • The carrier transport and exciton utilization in grain boundaries are achieved. • Two recombination channels ensure high efficiency and small efficiency roll-off. Passivation of the defect of perovskite films while maintaining efficient carrier transporting and exciton utilization in grain boundaries remains a substantial challenge. Here, in contrast to previously insulated polymers, two semiconductor TADF polymers were designed and synthesized as functional additives for perovskite light emitting diodes (PeLEDs) for the first time. The measured trap-filled limited voltages indicate that TADF polymer can act as efficient additive to reduce the non-radiative transition of the perovskite by passivating the defect and suppressing the Auger recombination. Moreover, the detail characterizations also demonstrated that the optimized polymer structure with flexible wrapping units appears to be beneficial for enhancing hydrophobicity, thermal stability, uniform crystallinity and high photoluminescence of the perovskite. As a result, the TADF polymer-modified PeLEDs achieve a high current efficiency of 66.1 cd A−1 and an external quantum efficiency of 17.4% with small efficiency roll-off and high color purity. Comparing to the standard PeLEDs, the notably three times higher enhanced device efficiency and stability fully highlight the potential of semiconductor TADF polymer as a functional additive to further develop high-performance perovskite electroluminescence devices. [ABSTRACT FROM AUTHOR]

[Display omitted] • Majority of artificial edible azo dyes such as Tartarazine are still used despite being banned. • MoS 2 /CQD/dendritic Ag composite acts as novel catalyst for degradation of Tartarazin. • A novel strategy used for the efficient synthesis of MoS 2 /CQD/dendritic Ag catalysts. • The result shows large application width for TZN degradation. • Z-scheme system could hinder electron-hole recombination and boost charge transfer. Nanocomposites of carbon quantum dots, molybdenum disulfide, and dendritic silver (MoS 2 /CQD/dendritic Ag) were synthesized via a facile and inexpensive procedure and utilized to investigate photocatalytic degradation of tartrazine (TZN) in aqueous medium. The nanocomposites and their individual components were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy dispersive spectrometry (EDS), mapping, X-ray photoelectron spectroscopy (XPS), and ultraviolet–visible diffuse reflectance spectroscopy (UV–Vis DRS). The optimum conditions for TZN degradation obtained were TZN concentration of 20 mg/L and a solution pH of 6.5. Electrochemical impedance spectroscopy (EIS) and photoluminescence (PL) analysis were employed to evaluate the TZN degradation by the prepared MoS 2 /CQD/dendritic Ag nanocomposites. XRD of CQDs, MoS 2 and Ag NPs showed amorphous, hexagonal phase and face-centered cubic structures, respectively. Band gaps of 3.3 and 1.9 eV for CQDs and MoS 2 , respectively as obtained from UV–Vis DRS. The enhanced photo-degradation of TZN was achieved due to the synergistic effects between the nanocomposite constituents. Complete degradation of TZN occurred within 30 min with a rate constant value of 0.172 min−1, wherein oxygen radicals played a significant role compared to other species during the process of degradation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hierarchically arrayed and defective MnCo 2 O 4 @NF was developed for photothermal CO-PROX. • The simple posttreatment process leads to the unique morphology and abundant defects. • The hierarchically nanoarrays enhance the light absorption and photo to thermal conversion. • More oxygen vacancies benefit to activate O 2 and alleviate electron-hole recombination. A novel strategy with the "three birds, one stone" effect has been proposed to enhance the catalytic performance of cobalt manganese spinel catalysts for photothermal CO-PROX in H 2 streams. The approach involves fabricating hierarchically arrayed defective MnCo 2 O 4 @ Nickel foam (NF) through a simple hydrothermal post-treatment and partial recrystallization process. Three synergetic effects were induced by the hydrothermal posttreatment of MnCo 2 O 4 : (i) the creation of a hierarchically arrayed morphology that strengthens light absorption and photo-to-thermal conversion, supported by finite-element method (FEM) simulations; (ii) the increased vacancy structures to alleviate significant electron-hole recombination; and (iii) abundant oxygen vacancy to facilitate oxygen adsorption and activation. These effects result in the unique hierarchically arrayed morphology and superior structural properties of MnCo 2 O 4 spinel, which significantly enhances the photothermal synergism and catalytic activity of MnCo 2 O 4 @NF in photothermal CO-PROX driven by simulated solar light. This work provides a simple and facile strategy for developing hierarchical and defective MnCo 2 O 4 spinel photothermal materials. [ABSTRACT FROM AUTHOR]

• The ACPP nanoeggs relieve hypoxic tumor microenvironment and elevate the generation of singlet oxygen (1O 2) in SDT. • The ACPP nanoeggs convert H 2 O 2 into hydroxyl radicals (•OH) for chemodynamic therapy (CDT). • The decoration of Pd increased the content ratio of Ce3+/Ce4+, significantly enhanced enzymatic activities of nanoeggs. There is an increasing appreciation for sonodynamic therapy (SDT) that is triggered by ultrasound (US) to treat deep-seated tumors noninvasively. Whereas, the low production of reactive oxygen species (ROS) limits its effect because of the rapid recombination of electron-hole (e–-h+) pairs in sonosensitizers. Herein, Au@CeO 2 -Pd-PFH (ACPP) nanoegg with significantly improved sonosensitization and Fenton-like catalyst was manufactured. Under the irradiation of US, the ACPP nanoegg exhibited improved efficiency of ROS production owing to the narrow bandgap of 1.72 eV and the efficient e–-h+ separation ability. Additionally, the designed ACPP nanoegg mimicked not only peroxidase activity to convert endogenous hydrogen peroxide (H 2 O 2) into hydroxyl radicals (•OH) for chemodynamic therapy (CDT) but also catalase activity to produce oxygen (O 2) for ameliorating hypoxia and enhancing SDT. The decoration of Pd increased the content ratio of Ce3+/Ce4+, significantly elevating the enzymatic activity of nanoegg. With further loading of perfluorohexane (PFH), which led to a transition under US irradiation, US imaging of the tumor was realized. Through both in vitro and in vivo experimental studies, the nanoegg developed in this work was demonstrated to be a promising strategy for cancer nanotheranostic. [ABSTRACT FROM AUTHOR]

[Display omitted] • Heterostructures possess an indirect bandgap with type-II band alignment. • Direct Z-scheme charge transfer mode enhances photocatalytic performance. • The Z-scheme ensures sufficient separation between oxidative and reductive sites. • Intrinsic electric field permits electron-hole recombination for inferior redox levels. • The radicals formed at the photocatalyst surface degrade the organic pollutants. • Pristine heterostructures do not favour hydrogen production. • S/Se vacancies provide most promising site for HER with Δ G H ∗ ∼ 0. Photocatalysis has emerged as an appealing strategy for environmental remediation and sustainable energy production. The density functional theory (DFT) approximations were employed to investigate the heterostructures (HTS) of 2H and 2H́ polymorphs of MoSi 2 N 4 / MoSX (X = S, Se) for photocatalytic applications. To ensure their applicability for water-splitting photocatalysis, we examined the heterostructures for desirable electronic properties. The structures (except 2H́-MoSi 2 N 4 /MoSSe) have a direct Z-scheme type-II alignment which further favors the carrier separation causing hydrogen and oxygen production at distant positions. The bandgaps of structures lie within the desirable range of 1.23 to 3 eV, favoring visible light absorption. The difference in the work function of monolayers (of about 0.5 to 1 eV) develops an electric field at the interface of HTS, causing the separation of carriers. The reduction potential lies between −3.8 to −4.6 eV, while the oxidation potential lies between −5.7 to −6.2 eV. It indicates that although oxidation potentials incorporate water redox levels, reduction potentials of some HTS do not. To ensure HER, Gibbs free energies were calculated. The vacancy defects at S/Se site gave Δ G H ∗ less than the catalytic threshold of 0.2 eV. Due to ultrafast charge transfer, broad spectral response, and improved photocatalytic capability due to the formation of radicals at the surface, heterostructures can act as a competitive choice over monolayers for water-splitting photocatalysis. [ABSTRACT FROM AUTHOR]

[Display omitted] • α-MnO 2 /g-C 3 N 4 Z-scheme heterojunction is in-situ constructed. • α-MnO 2 /g-C 3 N 4 can 100% mineralization of HCHO with the irradiation of solar-light at ambient temperature. • The mechanism of photothermal catalysis was discovered to be thermal-assisted photocatalysis rather than solar-light driven thermalcatalysis. Formaldehyde (HCHO), as the most common indoor air pollutant, undoubtedly poses a huge threat to people's health. It is of practical importance to achieve complete decomposition of HCHO to harmless CO 2 at room temperature. Herein, α-MnO 2 /g-C 3 N 4 Z-scheme heterojunction was constructed through the in-situ growth of α-MnO 2 nanowires on the surface of g-C 3 N 4 nanosheets. Owing to the construction of Z-scheme heterojunction, α-MnO 2 /g-C 3 N 4 composite exhibits excellent photothermal catalytic activity, achieving complete mineralization of HCHO with the illumination of 191 mW/cm2 solar-light at GHSV of 180 L/g cat ·h. Particularly, even under one sun and visible light radiation, the α-MnO 2 /g-C 3 N 4 composite can still maintain 60% and 68% HCHO conversion, respectively. The formation of α-MnO 2 /g-C 3 N 4 Z-scheme heterojunction not only effectively inhibits the photogenerated electron-hole pairs recombination, but also overcomes the band defects of the individual component. Furthermore, the mechanism of the photothermal catalysis of α-MnO 2 /g-C 3 N 4 composite was discovered to be thermal-assisted photocatalytic process rather than solar-light driven thermalcatalysis. On the one hand, the thermal energy generated from light radiation can accelerate the migration of photo-generated carriers and improve the separation efficiency of photogenerated electrons from vacancies; on the other hand, it can decrease the activation energy of lattice oxygen and produce more surface-active oxygen species. This work provides cost-effective strategies and suggestions for decomposing HCHO and other VOCs in indoor air at room temperature. [ABSTRACT FROM AUTHOR]

[Display omitted] • Interface-confined surface engineering via NaBH 4 etching toward efficent solar water splitting. • NaBH 4 etching at the semicoductor/OEC interface modulates the charge carrier pathway. • Synergy effect of NaBH 4 treatment and NiFeBi OEC extends charge carrier lifetime and reduces electron-hole recombination on semiconductors. • A photocurrent density of 6.33 mA cm−2 at 1.23 V RHE with a high STH efficiency of 2.3% on NiFeBi/R-BiVO 4. • A feasible and versatile approach addresses the bottle-necks of PEC water splitting activity and stability. Photoelectrochemical (PEC) water splitting is a promising strategy for solar energy conversion and storage. However, poor charge transfer and sluggish water oxidation reaction restrain the PEC performance. Herein, we propose a simple and effective interface etching strategy on the semiconductor surface to modulate the photoanode/cocatalyst interface, following by the decoration of NiFeBi oxygen evolution catalyst (OEC) for significantly improved oxygen evolution activity and stability of the BiVO 4 photoanode. The resultant photoanode achieves a record photocurrent density of 6.33 mA cm−2 at 1.23 V RHE under one sun illumination, over approximately 3.63 times higher than that of the pristine BiVO 4. The applied bias photon-to-current efficiency of 2.3% can be attained with showing a good durability of 40 h. Systematic studies have demonstrated that the introduction of electron-deficient state of B accelerates the surface trapping hole and the charge transfer, which enhances the interfacial coupling between BiVO 4 and NiFeBi OEC, and strongly drives the hole from the BiVO 4 to the NiFeBi surface for capable water oxidation. Density functional theory calculations prove that the surface B treatment increases the effective number of reaction paths of OER and the density of electronic states near the Fermi energy level, which improves the electrical conductivity of the BiVO 4 /OEC interface. This work provides a feasible strategy for tailoring the interface engineering to significantly enhance the PEC activity and stability of the photoanodes. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new composite photocatalyst was conceived and fabricated by growing CdS in situ on PCN-222(Pt). • Pt single atoms largely enhanced the utilization of photoinduced carries. • CdS@PCN-222(Pt)-3 showed an activity of 71.6 mmol/g CdS /h, which was 110 times higher than pure CdS. • CdS@PCN-222(Pt)-3 displayed an overall water splitting activity for hydrogen of 2.28 mmol/g CdS /h. Water splitting by photocatalytic semiconductors to produce hydrogen is considered one of the best ways to utilize solar energy. However, the recombination of electron-hole pairs in semiconductors such as cadmium sulfide (CdS) reduces the light-driven reaction efficiency. In addition, nanoparticles (NPs) of semiconductors tend to aggregate, resulting in decreased atom utilization. Rationally building composite photocatalysts by reducing nanoparticle aggregation and maximizing charge transport efficiency is thus seen as an attractive strategy for achieving high hydrogen evolution rates. Herein, we designed a new composite photocatalyst, CdS@PCN-222(Pt), by growing CdS in situ on a metal–organic framework (MOF) containing single Pt atoms. This catalyst exhibits an excellent hydrogen evolution activity of 71645 μmol/g CdS /h under visible light irradiation (λ ≥ 420 nm), which is around 110 times higher than pure CdS. Remarkably, CdS@PCN-222(Pt) also has an extremely high hydrogen evolution activity of 31326 μmol/g CdS /h under direct sunlight irradiation, far surpassing those of reported MOF-based photocatalysts. The charge-separation mechanisms were revealed by spectroscopic measurements, DFT calculations, and single crystal X-ray diffractions. The highly porous structure of PCN-222(Pt) results in the uniform distribution of CdS, and the anchored Pt single atoms achieve photo-induced electron transfer, inhibiting the recombination of photogenerated charge carriers. The results show that the synergistic effects between inorganic semiconductors and MOFs containing anchored single atoms enhance the photocatalytic activity for H 2 generation under visible light and even sunlight. As a result, the findings offer important new perspectives that can be utilized in the design of high-performance composite photocatalysts in the future. [ABSTRACT FROM AUTHOR]

[Display omitted] • A core/shell structural Cd 0.194 Zn 0.806 Se 0.406 S 0.594 /ZnS QD is synthesized. • The alloyed QD owns a near-unity QY and reduced non-radiation Auger recombination. • The QLED shows a high luminance of over 105cd m−2 and a peak EQE of over 20%. • The high efficiency is due to high QY and balanced charge carrier injection. Near 100% photoluminescence quantum yield (PL QY) is the first target for designing luminescent quantum dots (QDs). Here, an alloyed QD with a core/shell structure of Cd 0.194 Zn 0.806 Se 0.406 S 0.594 /ZnS is synthesized and characterized by the feature of large core size (about 10 nm) and thin shell (around three ZnS monolayers). It exhibits an efficient green emission with the PL QY of 99.8% and ultra-fast radiative transition rate (k r) of 4.16 × 107 s−1. It demonstrates that the excited state will be rapidly decayed to its ground state through a radiative channel and less vulnerable to non-radiative processes. Under a high pump intensity (254.65 μJ cm−2), the Cd 0.194 Zn 0.806 Se 0.406 S 0.594 /ZnS QD still owns a long biexciton decay lifetime (τ xx) of 1.05 ns and high biexciton QY xx of 25.1%, corresponding to a suppressed non-radiative Auger recombination. The Cd 0.194 Zn 0.806 Se 0.406 S 0.594 /ZnS QD based light-emitting diode exhibits a peak external quantum efficiency of 20.1% and brightness of over 105 cd m−2 at 5.2 V. We believe that the Cd 0.194 Zn 0.806 Se 0.406 S 0.594 /ZnS QD not only provides a near-unity QY but also ensures its QD based light-emitting diode (QLED) with an excellent performance, which could be an excellent QD material for QLED applications. [ABSTRACT FROM AUTHOR]

• A new type I mechanism is developed for accelerating the generation of superoxide anion radicals. • Three kinds of nanoscale covalent organic frameworks show tunable local polarization. • The presented COFs have excellent anticancer efficacy in vitro and in vivo. • The reticular polarization engineering of COFs enriches the fundamentals of type I PDT pathway. The exploration of type I mechanism remains a great challenge in photodynamic therapy (PDT) due to the limited electron transfer from the photosensitizer to ground state oxygen to form superoxide anion radical (O 2 −). In this study, we design three kinds of nanoscale covalent organic frameworks (COFs) with tunable local polarization for accelerating the generation of O 2 −. Among three COFs, the tetrakis-(4-formylphenyl)benzene-based COF (TB-COF) exhibits highly aggravated local polarization with 3.29 Debye of the dipole moment, and thus drives the photoinduced e− reduction of O 2 /O 2 −, which matches with the energy level of TB-COF. The elongated charge-separated state of TB-COF is also identified by femtosecond transient absorption spectra and time-dependent density functional theory calculation. Significantly, the inhibited electron-hole recombination of COFs further improves the O 2 − production efficiency upon protonation and thus strengthens anti-cancer effect in the acidic microenvironment of tumor cell or in vivo. The reticular polarization engineering of COFs provides a new type I PDT paradigm in biomedical applications. [ABSTRACT FROM AUTHOR]

• A Type II heterojunction consisting of BiVO 4 and diamond-like carbon. • Threefold improvement of photoelectrochemical performances and better stability was achieved for BiVO 4 /DLC photoanodes. • Band bending and depletion layers are the key factors for the enhancement. • The sp2 carbon phase acts as a conductive channel and the sp3 carbon phase provides stable support and passivation effect. Photoelectrochemical (PEC) water splitting is a promising technology to produce renewable hydrogen, which still faces problems of low photoelectric efficiency and instability. This work introduces a novel Type II heterojunction consisting of BiVO 4 thin film and diamond-like carbon (DLC) to the PEC system as a photoanode and achieves an increased PEC water-splitting activity. Compared to the pure BiVO 4 , the BiVO 4 /DLC heterojunction has an increased photocurrent density from 0.79 mA cm−2 to 2.39 mA cm−2 at 1.23 V vs RHE, and the IPCE from 4.8 % to 23.4 %. After 120 min (180 cycles) of PEC water splitting, the BiVO 4 /DLC heterojunction retains up to 82.3 % of the initial photocurrent density value, while the pure BiVO 4 has only 33.99 % remaining under the same conditions. Furthermore, the PEC system of BiVO 4 /DLC reaches the evolution rate of hydrogen of over 0.32 mmol h−1 cm−2, which is much higher than that of its counterparts. We ascribe the enhancement in PEC performance to the Type II heterojunction photoanodes that greatly promote carrier mobility and reduce the recombination rate of electron-hole pairs. We also identify that the band bending and depletion layer are the main reasons for the decrease in charge transfer and interface resistance. It is demonstrated that the sp2 carbon phase in DLC acts as a conductive channel to improve the separation and migration efficiency of free carriers, while the sp3 carbon phase provides stable support and passivation effect to the photoanode, thereby leading to an enhancement for both PEC water splitting performance and the long-time stability. This work provides an effective way to improve the BiVO 4 photoanode-based PEC water-splitting systems. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ag@SrTiO 3 -TiO 2 achieve high photocatalytic denitrification rate and N 2 selectivity. • Hollow double-shelled structure enhance light harvesting via multiple reflections. • Electron sink of Ag0and transport bridge of Ti3+ induce construction of Z-scheme. • Z-scheme heterostructure enhance the charge separation and redox powers. • Photogenerated electron and CO 2 − participate in photocatalytic denitrification. Hollow double-shelled Ag@SrTiO 3 -TiO 2 with Z-scheme heterostructure was constructed for highly efficient photocatalytic reduction of nitrate to N 2. The 3D finite-difference-time-domain analysis indicated that hollow double-shelled structure improved light harvesting due to multiple reflections. Photo-generated electrons transfer from SrTiO 3 to Ag0 caused by electron sink effect were utilized to reduce nitrate, while photo-generated electrons of TiO 2 migrated to SrTiO 3 via transport bridge of Ti3+ defects for electron–hole recombination. Such charge carriers migration pathway facilitated the construction of Z-scheme heterostructure, which enhanced charge separation yet still retained high redox powers. Both photogenerated electrons and CO 2 − played important role in photocatalytic denitrification. Furthermore, Ag0 acted as co-catalyst which not only promoted photogenerated electrons transfer to nitrate but also enhanced nitrate conversion selectivity to N 2. Combining the above advantages, nitrate removal rate and the nitrogen selectivity reached 97.2 % and 98.8 % within 60 min, respectively. Even after five cycles, it still remained satisfied photocatalytic activity and stability. In summary, this work proposed a feasible strategy to construct Z-scheme hollow double-shelled photocatalyst for efficient photocatalytic denitrification. [ABSTRACT FROM AUTHOR]