Search

[Display omitted] • Design of a Bi 2 O 3−x /NiAl-LDH S-scheme heterojunction to promote the separation of carriers. • Utilizing the LSPR effect to boost photothermal-assisted photocatalytic CO 2 reduction. • The introduction of Bi 2 O 3−x extends the photoresponse to long wavelength region. In this study, a new type of 2D/2D Bi 2 O 3−x /NiAl-LDH (BO/NA-LDH) S-scheme photocatalyst was prepared by combining NiAl-LDH with Bi 2 O 3−x by wet chemical deposition for obtaining efficient photothermal-assisted photocatalytic reduction of CO 2 under simulated sunlight irradiation. In particular, the as-prepared optimal 50-BO/NA-LDH sample exhibited the CO production yield of 83.55 ± 2.76 μmol/g/h, which was 9 and 27 times that of BO (9.32 ± 0.62 μmol/g/h) and NA-LDH (3.09 ± 0.38 μmol/g/h), respectively. The enhancement of photothermal-assisted activity over the 50-BO/NA-LDH system was mainly attributed to the coupling of the photothermal conversion performance of Bi 2 O 3−x and improving the migration efficiency of interface carriers of S-scheme heterojunction and 2D/2D structure. This study presents a promising strategy for the development of high-efficient photothermal-assisted photocatalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • WB 5-x as efficient cocatalyst for photocatalytic applications is proposed. • 5 wt% WB 5-x -WB 2 /TiO 2 possesses 23 times higher H 2 production rate than TiO 2 (81 H 2 µmol h−1 g cat –1) • 10 wt% WB 5-x -WB 2 /TiO 2 shows 4 times higher CO 2 RR rate than TiO 2 (108 µmol h−1 g cat –1) • New application direction for transition metal borides in photocatalysis is proposed. Catalytic reactions play an important role in modern industry as almost 90 % of the chemical industry is based on catalytic reactions. The development of new, more efficient catalysts will allow significant advances in chemical production, but still remains a rather challenging problem for materials scientists. Here, we have proposed and investigated a new composite photocatalyst based on WB 5-x -WB 2 and TiO 2 for H 2 evolution from aqueous ethanol solution and CO 2 reduction under visible light irradiation (410 nm). New composite photocatalysts WB 5-x -WB 2 /TiO 2 were synthesized and characterized by X-ray diffraction, UV–vis spectroscopy, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy. Photocatalytic measurements show that the maximum activity of the composite photocatalyst 4 and 23 times higher than the activity of unmodified TiO 2 in CO 2 reduction and H 2 evolution, respectively. Density functional calculations of the proposed reaction are in agreement with the provided experiments confirming the higher efficiency of the modified catalyst compared to TiO 2. [ABSTRACT FROM AUTHOR]

[Display omitted] • The bifunctional Bi 2 O 2 S/CAU-17 heterojunction was constructed. • The prepared composite exhibited high photocatalytic activity for simultaneous TC degradation and CO 2 reduction. • TC can regard as a hole sacrificial agent as well as CO 2 resource. • The possible mechanism for the high performance was investigated. To address the issues of energy scarcity and environmental pollution, a photocatalytic coupling system is employed to simultaneously harness electrons and holes in a single photocatalytic system. The current study presents a novel approach to construct a dual reaction pathway system for tetracycline hydrochloride (TC) oxidation and CO 2 reduction. Herein, Bi 2 O 2 S/CAU-17 composite was designed and fabricated through a facile solvothermal method. The hybrid photocatalyst exhibited an excellent performance for simultaneous TC degradation and CO 2 reduction. The CO-production rate can be reached 22.0 μmol g-1h−1 through the optimized 20% Bi 2 O 2 S/CAU-17 sample. Notably, the source of CO 2 in the reaction system is solely derived from the photoxidation of TC. The theoretical calculations and experimental findings have shown that the existed Bi 2 O 2 S can enrich electron and separation of photo-generated electrons from CAU-17, thus, the holes in Bi 2 O 2 S and CAU-17 can be involved in the photodegradation of TC. Afterwards, the CO 2 generated by TC oxidation moves to Bi 2 O 2 S via diffusion of molecules and could be efficiently reduced by electrons to produce CO. The development of this novel bifunctional Bi 2 O 2 S/CAU-17 hybrid photocatalytic system could provide valuable insights for the advancement of photocatalytic coupling reaction systems. [ABSTRACT FROM AUTHOR]

[Display omitted] • Oxygen vacancies modulated BiOBr nanosheets was prepared by the treatment of NaBH 4. • The electron density around Bi atoms near the oxygen vacancies could increase after the construction of oxygen vacancies. • The accelerated separation of photogenerated charge boosts CO 2 and Cr(VI) photoreduction. Unsatisfactory charge separation ability and insufficient active sites are the main factors leading to low efficiency for photocatalytic CO 2 conversion and Cr(VI) reduction. Constructing surface defects to accelerate charge separation is an effective strategy for promoting photocatalytic process. Herein, the oxygen vacancies modulated BiOBr nanosheets were constructed by NaBH 4 solution treatment. Density functional theory calculation results found that the formed oxygen vacancies would increase the electron density around Bi atoms near the oxygen vacancies, and inhibiting recombination of the photoinduced carriers. Besides, abundant oxygen vacancies can effectively enhance the adsorption of CO 2 molecules. Therefore, the BiOBr with rich oxygen vacancies (BiOBr-ROV) shows higher evolution rates for CO (15.66 μmol g−1) and CH 4 (0.22 μmol g−1) under irradiation of 300 W Xe lamp for 4 h compared with pristine BiOBr nanosheets (BiOBr) and BiOBr with deficient oxygen vacancies (BiOBr-DOV). The intermediate products in the CO 2 reduction process have been detected by in-situ Fourier-transform infrared spectroscopy. Besides, the photodegradation activity of Cr(VI) over BiOBr-ROV is 98.65% under 80 min of irradiation, which is higher than that of BiOBr (78.01%) and BiOBr-DOV (53.67%). The work provides a new possibility to construct photocatalysts with high-performance for solar energy conversion. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cu-porphyrin (CuPor)/Ru-pincer complex (RuN 3) polymer are in-situ coupled on Cs 0.33 WO 3. • Organic-inorganic Z-scheme heterojunction formed via ester bond and H-bond interactions. • A cascade Z-scheme charge transfer mechanism proceeds in the CoPor-RuN 3 /CsWO composite. • CsWO's electrons can combine with the polymer's holes via the interfacial heterojunction. • Cu/Ru sites of CoPor-RuN 3 polymer promote electrons enriching on Ru center for CO 2 RR. The photocatalytic system that simulates the principle of photosynthesis is considered one of the most promising technologies for converting CO 2 into chemical fuels. Herein, copper tetra(4-carboxyphenyl)porphyrin (CuPor)-ruthenium 2,6-bis(5-amino-benzimidazol-2-yl)pyridine pincer complex (RuN 3) coupled polymer (CuPor-RuN 3) is in-situ polymerized on hexagonal tungsten bronze Cs 0.33 WO 3 (CsWO) nanoparticles to construct a novel CuPor-RuN 3 /CsWO composite photocatalyst with cascade charge transfer mechanism, where the inorganic–organic Z-scheme heterojunction at the CuPor-RuN 3 /CsWO interface and the Z-scheme molecular junction (-[CuPor-RuN 3 ]-) within the polymer facilitate photoexcited electrons transferring from CuPor units to RuN 3 ones, and finally enriching on Ru sites for boosting the CO 2 reduction reaction (CO 2 RR). Under visible light irradiation and 1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]imidazole serving as electron donor, the resultant CuPor-RuN 3 /CsWO delivers average CO/CH 4 yields up to 4645/89 μmol g-1h−1, corresponding to an overall photoactivity of 10002 μmol g-1h−1, which is 20 times higher than that of the single polymer. These results provide new ideas for exploring high-performance artificial photosynthesis system to convert CO 2 into chemical fuels. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel Fe 3 O 4 @ZIF-8@BiOX (X = Cl, Br, I) composite photocatalyst was developed. • Synergistic removal of OTC-Cr(VI) was optimized by regulating halide ion type. • Fe 3 O 4 @ZIF-8@BiOI masters the fate of pollutants through surface-active substances. • OTC and Cr(VI) interacted on the surface of Fe 3 O 4 @ZIF-8@BiOI. • The designed method holds potential for practical wastewater removal and recycling. The magnetic Fe 3 O 4 @ZIF-8 with high adsorption properties and easy separation were embedded in BiOX (X = Cl, Br, I) to synthesize Fe 3 O 4 @ZIF-8@BiOX using a simple one-pot solvothermal strategy. The crystal structure, surface morphology, photoelectric properties, thermal stability and magnetic response of the three materials were compared and analyzed, and the effect on the removal of OTC and Cr(VI) from single and coexisting systems by adsorption-photocatalysis is discussed. The results show Fe 3 O 4 @ZIF-8@BiOI has the highest separation efficiency of photogenerated carriers upon photoexcitation and stronger light absorption capacity, and exhibits better adsorption-photocatalytic activity than the other two materials in the photocatalytic reduction of Cr(VI) (68 % and 65 % removal for single and coexisting systems) and degradation of OTC (86 % and 59 % removal for single and coexisting systems). It is noteworthy that in the coexistence of Cr(VI) and OTC, a slight decrease of removal occurred, which could be due to a competitive effect between two pollutants being greater than the synergistic effect. ∙O 2 - is the main active substances in the adsorption-photocatalysis process. Finally, this work demonstrates the excellent adsorption and photocatalytic ability of Fe 3 O 4 @ZIF-8@BiOI for the simultaneous removal of Cr(VI) and OTC, which has great potential for practical wastewater treatment. [ABSTRACT FROM AUTHOR]

This study employed carbonized pomelo peel (CPP), a waste biomass material, to successfully craft a CN@CPP/BOCB-OV ternary heterojunction abundant in N/O vacancy defects. Compared with the pristine single material the photocatalytic activity of the heterojunction system was increased by 55.0 times and 35.6 times respectively. Importantly, the heterojunction demonstrated the ability to reduce CO 2 even under infrared light excitation, a crucial step for cascade sunlight utilization. Through a series of characterizations, experiments and DFT calculations, we revealed the coupling effect of CPP as a multi-site cooperative center with the double defects and built-in electric field in the heterojunction system. Subsequently, the photocatalytic activity enhancement mechanism has been elucidated. This work combines the strategies of waste biomass utilization, heterostructure construction and defect engineering, achieves the multi-site synergistic enhancement for CO 2 photoreduction, and offers a promising approach in designing efficient heterostructure photocatalysts. [Display omitted] • The synthesized heterojunction exhibits the capacity to reduce CO 2 under infrared light irradiation. • The g-C 3 N 4 @CPP/BiOClBr-OV shows high yield and selectivity of CO production in photocatalytic CO 2 reduction. • The introduction of CPP enhances the interface electric field within the initial heterojunction. • g-C 3 N 4 @CPP/BiOClBr-OV achieves the three-in-one combination of photothermal sites, electron concentration sites, and CO 2 adsorption active sites. • The electron transfer mechanism at the heterojunction interface has been elucidated. In recent years, there has been significant interest in generating high-value solar fuels via the photocatalytic reduction of CO 2. Nonetheless, its large-scale application is impeded by low energy utilization efficiency and limited photocatalytic activity. This study employed carbonized pomelo peel (CPP), a waste biomass material, to successfully craft a CN@CPP/BOCB-OV ternary heterojunction abundant in N/O vacancy defects through secondary calcination and in-situ growth. The construction of the heterojunction and the emergence of defect-induced donor energy levels create a built-in interface electric field (IEF) and an interfacial electron transmission channel respectively, fortifying the separation and transport of photogenerated electrons. Crucially, following the incorporation of CPP, its distinctive 3D porous and heterojunction bionic flower structures expand the spectral absorption range. Acting as a superior electron acceptor, CPP reinforces the IEF, notably boosting carrier transport efficiency. Simultaneously, it operates as a hub for photothermal synergy and CO 2 adsorption activation, achieving multi-site synergistic enhancement of photoreduction CO 2 activity. Hence, the CN@CPP/BOCB-OV heterojunction demonstrates a substantial quantitative enhancement in CO 2 photoreduction activity. Remarkably, it exhibits the capability to catalyze CO 2 reduction even under infrared light excitation, which is of great significance for the cascade utilization of solar energy. Furthermore, employing DFT calculations, we elucidate the electron transfer mechanism at the heterojunction interface and outline potential pathways for photocatalytic CO 2 reduction. The combination of waste biomass utilization, heterostructure construction and defect engineering provides a promising strategy for developing efficient heterostructure photocatalysts. [ABSTRACT FROM AUTHOR]

The sulfur-doped carbon nitride (SCN-X) nanosheets were fabricated by condensing g-C 3 N 4 with thioacetamide (TAA), leading to abundant S⋯H N bridges, altered surface hydrophilicity, extended photo-responsive region and improved charge transfer. We further prepared functionalized polyvinylidene fluoride (PVDF) membrane with obtained SCN-3, indicating optimal H 2 O 2 generation of 1491 μmol L–1h−1 (3.73 mmol g–1h−1) and H 2 evolution of 16.3 mmol g–1h−1 under monochromatic LED light irradiation. [Display omitted] • S-doped CN nanosheets were obtained by condensing g-C 3 N 4 with TAA, forming S⋯H N bridge to induce fast charge transfer. • S-doping induced edge S⋯H N bridge could alter surface hydrophilicity and extend the photo-responsive region up to 700 nm. • The SCN-3 photocatalyst coated PVDF membrane indicates significantly improved bifunctional H 2 O 2 and H 2 production activities. The utilization of green and pollution-free solar energy for photocatalytic reduction of oxygen (O 2) to hydrogen peroxide (H 2 O 2) is a highly desirable technology. In this work, sulfur (S)-doped graphitic carbon nitride (SCN) nanosheets were prepared by co-condensation of carbon nitride with thioacetamide as a sulfur source. The substitution of sp2 hybridized N atoms by S atoms created S⋯H N bridges through weak hydrogen bonds, promoting fast carrier separation and transfer. Moreover, the S-doping could effectively reduce the band gap by approximately 0.6 eV, and thereby expand photo-responsive region of SCN-based photocatalysts up to 700 nm. To gain the practicability and retrievability of prepared photocatalysts, we developed SCN-based nanomaterials functionalized polyvinylidene fluoride (PVDF) membranes for H 2 O 2 production and H 2 evolution. The optimized photocatalytic efficiency of SCN-3 reached 1491 μmol L–1 h−1 of H 2 O 2 generation and 16.3 mmol g–1 h−1 of H 2 evolution under monochromatic LED light irradiation, nearly 2–5 times higher than the state-of-art metal-free photocatalysts. These findings offer new insights into the doping regulated nanocatalysts functionalized membranes to achieve high performance in practical applications. [ABSTRACT FROM AUTHOR]

In this paper, a Bi 4 V 2 O 11 /SWNT/g-C 3 N 4 S-scheme heterojunction photocatalyst was reasonably constructed to achieve efficient photocatalytic CO 2 reduction.This job is prospective to offer more empirical reference for the construction of higher activity g-C 3 N 4 photocatalytic materials. [Display omitted] • The ultrathin porous nanosheets have large specific surface area and more active sites. • Oxygen vacancies increase the adsorption capacity of CO 2. • SWNTs can increase the charge separation efficiency even further. • S-scheme heterostructure can increase the effectiveness of photogenerated carrier separation. • The Bi 4 V 2 O 11 /SWNT/g-C 3 N 4 S-scheme heterojunction catalyst has good photocatalytic performance. A novel Bi 4 V 2 O 11 /single-walled carbon nanotube (SWNT)/g-C 3 N 4 S-scheme heterojunction photocatalyst is prepared using an in situ solvothermal growth method. Heterostructures are constructed by coupling the defective semiconductor Bi 4 V 2 O 11 with ultrathin porous g-C 3 N 4 nanosheets. To improve the photocatalytic CO 2 reduction activity, oxygen defects are used to enhance electron capture and CO 2 adsorption, the S-scheme heterojunction is used to improve the separation efficiency of the photogenerated carriers and SWNTs are used to form high-speed electron transport channels. The experimental results indicate that the maximum CO formation rate of Bi 4 V 2 O 11 /SWNT/g-C 3 N 4 is 18.6 μmol h−1 g−1, which is 2.7 and 2.4 times that of the ultrathin porous g-C 3 N 4 nanosheets and Bi 4 V 2 O 11 heated for 15 h, respectively, and 3.4 times that of standard g-C 3 N 4. This work provides a vital reference point for the in situ construction of S-scheme heterojunctions with defects. [ABSTRACT FROM AUTHOR]

[Display omitted] • A monolithic 3D Z-scheme photocatalyst was developed for CO 2 to CO conversion. • Bi 2 WO 6 /g-C 3 N 4 /Cu foam shows high CO yield and stability under visible light. • The enhanced CO 2 reduction performance and mechanism were analyzed. • Novel strategy for efficient photocatalytic CO 2 reduction. Photocatalytic CO 2 reduction to hydrocarbon fuels represents a promising solution to CO 2 emission challenges. However, photocatalytic CO 2 reduction systems face hurdles in practical utilization for the low efficiency of photocatalysts and challenge in catalyst immobilization. Therefore, a novel monolithic three-dimensional Z-scheme photocatalyst was synthesized by fabricating Bi 2 WO 6 /g-C 3 N 4 heterojunction on Cu foam substrate (Bi 2 WO 6 /g-C 3 N 4 /Cu foam) via thermal polymerization and electrophoresis deposition. A series of characterization results, including X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy and N 2 adsorption–desorption, illustrate the crystalline properties, pore structure, and morphology of the composite photocatalyst. Consequently, Bi 2 WO 6 /g-C 3 N 4 /Cu foam achieved CO production yield of 33.84 μmol/g cat under visible light illumination for 6 h and retained 96.2 % of initial photocatalytic activity after 30 h of reaction. UV–Vis diffuse reflection spectra, photoluminescence spectra and photoelectrochemical analysis was involved to reveal the mechanism of the photocatalytic activity of composite photocatalyst. The synergistic effect of the Z-scheme mechanism and the hierarchical macroporous structure improves the light absorption, light-induced electron-hole pair separation, and charge transmission. This catalyst construction strategy provides a viable approach for facilitating practical photocatalytic CO 2 reduction. [ABSTRACT FROM AUTHOR]

[Display omitted] • A Z-scheme Fe3+-Bi 2 WO 6 /PPy photoreduction system was constructed for Cr(Ⅵ) removal. • The introduction of Fe3+ and citric acid promoted the production of CO 2.•−. • The system had prominent reduction rate with 98.24 % Cr(VI) removal within 10 min. • A equation of organics' structure and Cr(Ⅵ) reduction rate was established. • The underlying photocatalysis mechanism was proposed. The hexavalent chromium (Cr(VI)) in wastewater poses a significant threat to the environment and human health. Photocatalytic reduction for the removal of Cr(VI) shows great potential for application. Herein, we present the construction of a direct Z-scheme Fe3+-Bi 2 WO 6 /PPy (PFBWO) photocatalyst for the Cr(Ⅵ) reduction in water via metal doping and polypyrrole in-situ deposition. A Cr(VI) reduction efficiency of 98.24 % is achieved in 10 min under visible light irradiation with a reduction rate constant of 0.275 min−1, which is 27.5 times higher than that of Bi 2 WO 6.The mechanistic studies reveal that doped Fe3+ introduces impurity energy bands and facilitates efficient separation of photogenerated electron-hole pairs via the induced built-in electric field (IEF). Furthermore, the sacrificial agent, citric acid (CA), introduced into the reaction system interacts with Fe3+ under the illuminated conditions to generate highly reducing •CO 2 −, which plays a crucial role in enhancing the reduction property. Additionally, the quantitative structure–activity relationship (QSAR) was used to analyze and establish the relationship between the structural properties of typical organic compounds and the reduction rate of Cr(VI) in the system. Therefore, this work can provide new insights for designing efficient and direct Z-scheme photocatalytic systems for the reduction of Cr(VI) in water. [ABSTRACT FROM AUTHOR]

[Display omitted] • We successfully crafted bimetallic UiO-66-NH 2 (Zr/Ni) photocatalyst. • The Ni2+ introduction can replace parts of Zr4+ to form the Ni-O-Zr bimetallic center. • The prepared sample promoted electron transfer and charge separation. • The synthesized samples exhibited excellent photocatalytic CO 2 to CO performance. Introducing a new metal into the metal center of metal–organic framework materials (MOFs) to alter their original electron transfer pathway to improve photocatalytic performance is a promising approach at present. Here, we report a one-pot method to introduce Ni2+ into the metal-centered Zr-O clusters of UiO-66-NH 2 (UN) to create a series of Ni2+-doped bimetallic materials (xNi-UN). Experimental results showed that the 0.5Ni-UN exhibited the highest photocatalytic CO 2 reduction activity, with a CO yield of 9.01 µmol g-1h−1 under visible light irradiation, which was 2.46 times higher than that of UN (3.67 µmol g-1h−1). Through a number of characterization analyses, we find that the doped Ni2+ replaced the part of original metal center Zr4+ to form a bimetallic UiO-66-NH 2 (Zr/Ni), which changed the energy band gap of UiO-66-NH 2 and improved the charge transfer. More importantly, the introduction of Ni2+ enhanced the efficiency of interfacial charge transfer from the organic ligand (2-aminoterephthalic acid) to the Zr-O cluster, enabling a metal-to-metal charge transfer (MMCT) pathway, which exhibited higher photocatalytic CO 2 to CO reduction activity. [ABSTRACT FROM AUTHOR]

[Display omitted] • 2D Carbon nitride polymer with both strong fluorescence and high photocatalytic reduction activity for Cr(VI) is prepared. • Multifunctional gel for the detection, adsorption, photocatalytic reduction and recycle of Cr(VI) is developed. • Multifunctional gel affords simultaneous sensitive detection of Cr(VI) by naked-eye and fluorescence. • Multifunctional gel shows high adsorption capacity towards Cr(VI). • Multifunctional gel provides high efficient photocatalytic reduction of Cr(VI) with visualization. It is of vital significance to explore effective and economical multifunctional materials for the detection, remediation and recycling of heavy metal (Cr(VI)). Herein, two-dimensional (2D) phenyl-modified carbon nitride (PCN) polymer was prepared through thermal polymerization of phenylguanidine carbonate. The incorporation of phenyl groups endowed PCN polymer with both strong green fluorescence and high photocatalytic activity for the reduction of Cr(VI). An multifunctional gel for simultaneous detection, adsorption, photo-reduction and recycling of Cr(VI) was further prepared by assembling PCN with polyethyleneimine–N,N'-methylenebisacrylamide (PEI-MBA) gel. PCN-PEI-MBA gel showed a sensitive fluorescence / colorimetric dual-mode detection of Cr(VI). Meanwhile, PCN-PEI-MBA gel displayed preeminent adsorption capacity of 3055.9 mg g−1, surpassing previously reported adsorbents. Under visible-light irradiation, the absorbed Cr(VI) in PCN-PEI-MBA gel was photocatalytically reduced into Cr(III) with visual real-time monitoring the detoxification process and Cr(III) can be further recycled as Cr 2 O 3 by calcination of PCN-PEI-MBA gel. Finally, PCN-PEI-MBA gel was utilize to adsorb and recycle Cr(VI) from the chromium-plating wastewater and detect the concentration of remaining Cr(VI) in the wastewater. This work provides an all-in-one treatment strategy for the detection, remediation and resource recycling of Cr(VI) in practical wastewater. [ABSTRACT FROM AUTHOR]

An in-situ topotactic transformation strategy is proposed for constructing CuO/Cu 2 O S-scheme hetero-nanosheets with abundant interfacial Cu(II)-O-Cu(I) bridges for boosted CO 2 photoreduction. The interfacial Cu(II)-O-Cu(I) bridges are found to provide fast transfer channels for photogenerated carriers transporting from CuO to Cu 2 O in an S-scheme pathway, leading to enhanced separation of photogenerated carriers. [Display omitted] • Cu 2 O/CuO HNSs are prepared by an in-situ topotactic transformation strategy. • The interfacial Cu(II)-O-Cu(I) bridges can provide fast transfer channels for photogenerated carriers. • The bond bridges can tune the kinetic and thermodynamic processes of the CO 2 -to-CO conversion. • Cu 2 O/CuO HNSs exhibit a high conversion rate of 22.14 μmol g−1 h−1 with a CO selectivity of 94.4%. Efficient charge transfer across interfaces is highly desirable, but remains challenging in engineering semiconductor heterojunctions for photocatalysis. In this work, hybrid hetero-nanosheets (HNSs) of CuO/Cu 2 O bridged with interfacial Cu(II)-O-Cu(I) have been constructed via an in-situ topotactic transformation strategy, in which CuO nanosheets are partially reduced by ascorbic acid and transformed into Cu 2 O. The interfacial Cu(II)-O-Cu(I) bridges are found to provide fast transfer channels for photogenerated carriers transporting from CuO to Cu 2 O in an S-scheme pathway, leading to enhanced separation of photogenerated carriers. Furthermore, the bond bridges can tune the kinetic and thermodynamic processes of the CO 2 -to-CO conversion at interfacial Cu(I) catalytic sites by altering the rate-determined step and shifting downwards d -band center of the Cu(I) sites. Owing to the interfacial Cu(II)-O-Cu(I) bridges, the optimized CuO/Cu 2 O HNSs significantly expedite the CO 2 photoreduction to CO, delivering a CO 2 conversion rate of 22.14 μmol g−1 h−1 with a CO selectivity of 94.4%, outperforming the state-of-the-art copper oxide-based photocatalysts. This work demonstrates an effective in-situ topotactic transformation strategy to create interfacial bond bridges at heterogeneous interfaces for boosted photocatalysis as well as the critical roles of interface catalytic sites for CO 2 conversion. [ABSTRACT FROM AUTHOR]

[Display omitted] • An innovative Cs 2 CuBr 4 /TiO 2 photocatalyst was developed by embedding Cs 2 CuBr 4 PQDs in a mesoporous TiO 2 matrix. • The Cs 2 CuBr 4 /TiO 2 heterojunction follows S-scheme charge transfer mode with boosted charge separation. • The mesoporous TiO 2 matrix promotes CO 2 adsorption and enhances the stability of Cs 2 CuBr 4 PQDs. • Cs 2 CuBr 4 /TiO 2 shows high photocatalytic activity and stability in CO 2 conversion. Halide perovskite quantum dots (PQDs) have shown great promise for the photochemical conversion of CO 2. However, the fast carrier recombination rates and inadequate adsorption/activation for CO 2 molecules have seriously restricted their practical application. Herein, an innovative step-scheme-based Cs 2 CuBr 4 /TiO 2 (CCB/TiO 2) photocatalyst was prepared by embedding Cs 2 CuBr 4 PQDs in a mesoporous TiO 2 matrix, which exhibits considerable potential as candidates for CO 2 photoreduction under simulated sunlight. Remarkably, the optimised CCB/TiO 2 photocatalyst delivered an impressive CO 2 reduction activity, which was 3.1 and 16.0 times higher than those achieved by pure Cs 2 CuBr 4 and TiO 2 , respectively. Furthermore, the S-scheme charge transfer mode was comprehensively corroborated by density functional theory (DFT) calculations, photo-assisted Kelvin probe force microscopy (KPFM), in situ irradiated X-ray photoelectron spectra (XPS), and electron spin resonance spectroscopy (ESR). On basis of theoretical calculations and in situ diffuse reflectance spectra (DRIFTS), the CCB/TiO 2 exhibited a reduced energy barrier of the rate-determining step, which facilitated the CO 2 photoreduction reaction. [ABSTRACT FROM AUTHOR]

[Display omitted] • A design strategy for a specific crystal plane coupled crystal/amorphous heterojunction has been proposed and validated. • Heterojunctions exhibit significant facet-dependence in terms of carrier separation efficiency. • The hierarchical pore structure of heterojunction increases the oxygen vacancy concentration and provides more transport channels. • Removal efficiency of 0.15 g/L Cr(VI) in 150 min was as high as 97 %. The difference in bandgap structure results in better charge separation performance of crystalline/amorphous heterojunctions compared to a single component. Considering that the catalytic activity of metal oxides is often accompanied by differences in facets, it has become an interesting topic to further improve the charge separation performance of such heterojunctions by adjusting the facets at the material contact interface. This article synthesized three novels ZnO/amorphous Bi 2 WO 6 heterojunctions with specific facets (ZnO-101/aBi 2 WO 6 , ZnO-100/aBi 2 WO 6 and ZnO-002/aBi 2 WO 6) by adding ZnO with different facets to bismuth tungstate precursors through hydrothermal methods. Photoelectric testing shows that compared to a single component, all three heterojunctions display efficient carrier separation characteristics. Among them, the ZnO/aBi 2 WO 6 heterojunction with the 002 facet exhibits more excellent performance, such as photocatalytic reduction of 150 mg·L−1 Cr(VI) without hole scavenger. The system spectral and energy spectrum characterization shows that the matched band structure induces a strong built-in electric field, which accelerates the separation of bulk carriers. And meanwhile, many oxygen vacancies, high specific surface area, low interface resistance and high concentration of carriers also provide help for the treatment of pollutants. In addition, 94.49 % of the photocatalytic activity was retained after 5 cycles, which proved the excellent photo cycling stability of the heterojunction. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pd, Rh, Cu ions modify the SrMoO 4 in form of surface species. • Pd, Rh, Cu-modified SrMoO 4 catalysts show enhanced photocatalytic activity. • Metal ion modifications increase adsorption sites and active surface regions. • Introduced species' energy levels match the potential of water oxidation. • Band engineering strategy enables selective photoreduction of CO 2 to CH 4. Photocatalytic CO 2 reduction holds promise as a strategy to mitigate the energy crisis and greenhouse effects. However, devising cost-effective photocatalysts capable of efficiently and selectively converting CO 2 to CH 4 remains challenging. This study presents the synthesis of Pd, Rh, and Cu-modified SrMoO 4 photocatalysts via a one-step solvothermal method. Our findings demonstrate increased CH 4 activity and controlled selectivity through the modification with Pd, Rh, or Cu ions. It was determined that Pd, Rh, or Cu ions modified the SrMoO 4 surface as -O-Pd-O-, -O-Rh-O-, or -O-Cu–O- species, increasing the adsorption sites and active regions on the catalyst surface. Moreover, these introduced -O-Pd-O-, -O-Rh-O-, or -O-Cu–O- species' energy level enhances visible light absorption and photogenerated charge carrier separation, and regulates the band structure for better alignment with water oxidation potential. This leads to greater water oxidation half-reaction efficiency and increased H+ generation in photocatalytic CO 2 reduction. Consequently, more protons (H+) participate in CO 2 photocatalytic reduction, thus promoting CH 4 production and selectivity. These insights may guide the design of highly-selective photocatalysts for effective CO 2 photoreduction through bandgap engineering strategies. [ABSTRACT FROM AUTHOR]

[Display omitted] • Highly stable lead-free perovskite Cs 2 AgBiBr 6 @UiO-66 nanocomposite was synthesized. • A typical Z-scheme heterostructure between the CABB nanocrystals and UiO-66 was constructed. • CABB@UiO-66 exhibited 38 and 40-fold improvement in catalytic activity than the individual components. • This work provides a guide for designing lead-free perovskite-based heterostructures. Excessive combustion of traditional fossil fuels causes seriously global warming (Carbon dioxide, CO 2) and energy crisis. Photocatalytic CO 2 conversion to fuels has emerged as one of the most effective strategies. Herein, an environmentally friendly nanocomposite based on lead-free Cs 2 AgBiBr 6 (CABB) perovskite nanocrystals and the UiO-66 metal–organic framework was fabricated by a facile ultrasonic process for efficient CO 2 photoreduction. The obtained CABB/UiO-66 consisted of uniform CABB nanocrystals (10–12 nm) attached to the UiO-66 surface and exhibited a high surface area (1031 m2/g). The composite displayed enhanced light-harvesting capacity than the individual components and provided sufficient active sites for promoting photocatalytic activity. A typical Z-scheme heterostructure between the CABB and UiO-66 was realized by forming an inner electric field, leading to the occurrence of efficient excited state charge transfer. The efficient charge transfer of CABB/UiO-66 inspired its use as an active photocatalyst for the reduction of CO 2 with significantly improved photocatalytic activity against its individual components. Specifically, CABB/UiO-66 exhibited 38 and 40-fold improvement in catalytic activity compared to respective CABB and UiO-66 in terms of the total yield of CO, CH 4 , and C 2 H 6. Moreover, the nanocomposite displayed excellent activity towards the oxidative photocatalytic degradation of aqueous environmental contaminant rhodamine B. We believe that this work provides a guide for designing lead-free perovskite-based renewable catalysts and offers new opportunities for the photocatalytic conversion of CO 2 photoreduction. [ABSTRACT FROM AUTHOR]

[Display omitted] • A one-dimensional hierarchical Bi 2 O 3 is developed high-performance photocatalyst. • Hierarchical Bi 2 O 3 exhibits rapid photodegradation capability for tetracycline and biphenol in solar light. • Cr(VI) is reduced efficiently by using Hierarchical Bi 2 O 3. • Superoxide (O 2 −) radical is verified as the major active species for photocatalytic reaction. A one-dimensional (1D) hierarchical Bi 2 O 3 is obtained by calcining hierarchical Bi 2 O 2 CO 3. Hierarchical Bi 2 O 3 exhibits good photocatalytic activity. Results show that 50 mg/L of Cr(VI) solution, 50 mg/L of tetracycline and 40 mg/L of biphenol A can be photodegraded in 10, 10 and 20 min under simulated sunlight with an apparent rate constant value of 0.331, 0.179 and 0.214 min−1, respectively. This enhanced photocatalytic performance is mainly ascribed to special hierarchical structure and the more negative CB position. Radical capture and EPR measurements all prove the superoxide (O 2 −) radical is the major active species for photocatalytic reaction. The transient photocurrent responses, PL emission and electrochemical impedance indicate 1D hierarchical Bi 2 O 3 displays an improved separation efficiency of photogenerated e-h pairs. These findings would inspire many research for developing high-performance catalysts using under simulated sunlight. [ABSTRACT FROM AUTHOR]

[Display omitted] • K/O-CN was synthesized by facile molten salt calcination for CO 2 photoreduction. • K/O-CN owned regular nanorod structure and introduced cyano terminal groups. • CO production rate of K/O-CN reached 7.5 times to pristine CN. • Surface area, CO 2 adsorption, and light absorption were enlarged for K/O-CN. • Dual-doping of K and O accelerated charge separation and CO desorption. Photocatalytic CO 2 reduction is a promising tactic to fix surplus CO 2 and generate high-value products. Non-metallic graphitic carbon nitride (CN) is a robust and inexpensive photocatalyst for CO 2 reduction, yet its efficiency remains limited by poor light absorption, sluggish charge kinetics, and low surface area. Here, we report K and O dual-doped CN (K/O-CN) synthesized by facile molten salt calcination for efficient CO 2 photoreduction. Distinctive from CN, K/O-CN owned regular nanorod structure and introduced cyano terminal groups, due to the reconstruction of C-N bond by interstitial K doping and substitutional doping of O within CN matrix. K/O-CN displayed a CO production rate of 4.5 ± 0.2 μmol g−1h−1, which was 7.5 times as much as pristine CN and surpassed the performance of O-CN or K-CN. The enhanced CO 2 reduction of K/O-CN was derived from its enlarged surface area and pore volume, magnified CO 2 adsorption capacity, and narrowed band gap with better visible light absorption. The dual-doping of K and O accelerated the charge separation and reinforced reduction potential with a more negative conduction band. DFT calculation reveals that dual-doping impeded charge recombination by increasing spatial distance between photoinduced electrons and holes and caused a kinetic preference for CO desorption. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cobalt phthalocyanine modified flower-like ZnIn 2 S 4 nanosheets were prepared. • The composites show great photocatalytic syngas generation from CO 2 reduction. • The ratio of CO/H 2 in syngas is tunable under visible light irradiation. • The flower-like ZnIn 2 S 4 composites demonstrate good photocatalytic durability. • The enhanced photocatalytic activity is contributed by dimension-matched heterojunction. Photocatalytic carbon dioxide (CO 2) reduction into syngas (the mixture of CO and H 2) has been considered as an attractive method to solve the greenhouse effect and energy shortage. Polychalcogenides semiconductors such as ZnIn 2 S 4 (ZIS) have been widely utilized in photocatalysis but are still hampered by limited photo-induced charge separation and poor product selectivity. Molecular catalysts for CO 2 reduction possess superior selectivity for specific reduction products but suffer from low stability and recycling difficulty. Herein, we modified a molecular phthalocyanine (Pc) on flower-like ZIS nanosheets. This hybrid exhibited enhanced photocatalytic CO 2 reduction and exhibited a tunable ratio of CO/H 2 in syngas (0.01–4.65) under visible light irradiation. The enhanced photocatalytic activity of ZIS-Pc hybrids can be attributed to dimension-matched ultrathin heterojunction, which facilitated charge separation, broad light utilization, and recycling stability. The unique design holds great potential for other highly efficient photocatalytic reactions. [ABSTRACT FROM AUTHOR]

[Display omitted] • OVs-BMO composite with small sized Cu nanodots were synthesized. • The Cu/ILs/OVs-BMO highly increased the charge separation efficiency. • The amino-functionalized ILs increased the photocatalytic reduction of CO 2. The conversion of CO 2 into useful chemical fuels through solar photocatalysis is an important means to alleviate energy and environmental problems. In this work, small-sized Cu nanodots were dispersed on the surface of bismuth molybdate containing oxygen vacancies. The Cu/ILs/OVs-BMO composite photocatalyst with high photocatalytic reduction activity was obtained. The small size of Cu nanodots can not only greatly improve the visible light absorption of the composite catalyst, but also establish an effective channel for charge transport through the close interaction between Cu nanodots and bismuth molybdate, which promotes the efficient separation of photogenerated charge carriers and increases the photocurrent by 11.04 times. The CO 2 photocatalytic reduction interface reaction was improved by adding an amine-based functionalized ionic liquid. The complexation of ILs and CO 2 decreased the activation energy of generating CO 2 intermediate and the overpotential of the reaction. Compared with BMO, the yield of the liquid products on Cu/ILs/OVs-BMO photocatalyst increased by 17.80 times. [ABSTRACT FROM AUTHOR]

[Display omitted] • The dual-plasma enhanced g-C 3 N 4 /Pd/MoO 3-x heterojunction was fabricated for high-selectivity photocatalytic CO 2 reduction. • The g-C 3 N 4 /Pd/MoO 3-x composites revealed excellent near-infrared absorption ability. • The carrier separation efficiency was effectively improved under the synergistic effect of MoO 3-x and Pd nanosheets. • The g-C 3 N 4 /Pd/MoO 3-x S-scheme heterojunction displayed high photocatalytic performance and CO selectivity. • The S-scheme charge transfer mechanism was proposed based on UPS and ESR results. The localized surface plasmon resonance (LSPR) effect has shown significant progress in enhancing the efficiency of light absorption and separating photogenerated carriers. Herein, the dual-plasma enhanced 2D/2D/2D g-C 3 N 4 /Pd/MoO 3-x (CPM) S-scheme heterojunction photocatalysts were synthesized using the method of hydrothermal and electrostatic self-assembly for high-selectivity photocatalytic reduction of CO 2 to produce CO. The dual LSPR effect of MoO 3-x and ultrathin Pd nanosheets synergistically broadened the optical response range of the CPM composites and successfully improved the photocatalytic activity and near-infrared (NIR) performance. The optimized CPM-30 photocatalysts exhibited CO yields of 18.55 μmol g−1 with a selectivity of 96.3%. In addition, the CO yield reached 3.92 μmol g−1 after 4 h of NIR light photoirradiation. The electron spin resonance (ESR) and ultraviolet photoelectron spectroscopy (UPS) tests showed that the S-scheme heterojunctions were constructed by coupling g-C 3 N 4 /Pd nanosheets and MoO 3-x. This work will provide a reference for improving product selectivity through the design of two-dimensional composites and the utilization of plasma materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • The moderate-strength CO 2 adsorption sites related to surface cobalt atoms determine the catalytic activity and CO selectivity in CO2-to-CO reaction. • The CO evolution activity and CO selectivity of Co 3 O 4 catalysts are controlled by the surface atomic arrangement of Co2+ and Co3+. • The Co 3 O 4 with rich exposure of Co2+ exhibits high activity and CO selectivity owing to a combination of improved separation of charge carriers, O-defects that promote the adsorption and activation of CO 2 , as well as the Co2+ site that facilitate the desorption of CO product. Transition metal oxides (TMOs) have been proposed as potential candidates for CO 2 photoreduction (CO 2 RR). Nonetheless, they often exhibit low efficiency and poor selectivity. Understanding how structural surface features influence photocatalytic reactions is crucial for the development of efficient catalysts. Unfortunately, the intricate structure of TMOs often hinders the thorough understanding of their structure–activity relationships. In this study, three spinel Co 3 O 4 nanocrystals with different planes are used as model catalysts to systematically investigate the structure sensitivity for CO 2 RR. According to both experimental results and theoretical calculations, Co 3 O 4 with a higher exposure of Co2+ is more effective in the photoreduction of CO 2 to CO. This can be attributed to a combination of factors including improved separation of charge carriers, O-defects that promote CO 2 activation and the Co2+ sites that facilitate the desorption of CO product. Moreover, the CO 2 RR performance over Co 3 O 4 catalysts can be controlled by the surface atomic arrangement of Co2+ and Co3+, which through affecting a tradeoff between activating the CO 2 reactant and releasing the CO product. Therefore, the proper control of Co2+/Co3+ ratio on the surface of Co 3 O 4 can optimize the reaction performance. This study provides guidance for designing highly active and cost-effective TMO-based catalysts for CO 2 RR. [ABSTRACT FROM AUTHOR]

A composite photocatalyst consisting of pururin (pp) and dodecyl sulfonate (SDS) co-intercalated ZnAl LDHs was designed and constructed based on the intercalation and assembly characteristics of LDHs, the interlayer photostability of photosensitive molecules were significantly improved. Combining the matching energy level relationship between pp and LDHs, the visible photocatalytic reduction performance of CO 2 was improved, and the yield of CO was 12 times higher than that of ZnAl LDHs. [Display omitted] • A photosensitive molecule/LDHs nanocomposite photocatalyst was constructed through the intercalation and assembly characteristics of LDHs. • The photostability of photosensitive molecules(pp) between layers is improved. • SDS-pp(x%)/LDHs exhibits enhanced visible photocatalytic reduction of CO 2 performance. Purpurin(pp) can be used as a photosensitive molecule in photocatalytic systems due to its excellent absorption of visible light, but its application is limited due to its poor stability under light. Layered double hydroxides (LDHs) can act as molecular containers due to their interlayer anion exchangeability, introducing target anions into the interlayer of LDHs and improving the instability of anions by utilizing the 2D confinement environment between LDHs layers. A series of co-intercalation materials with different ratios of pp and dodecyl sulfonate (SDS) were prepared through the hydrothermal method in this work, denoted as SDS-pp(x%)/LDHs. Compared with pp, the absorbance retention rate of SDS-pp(x%)/LDHs increased from 12.5% to 90% after 5 h of light exposure. Then its potential application in visible photocatalytic reduction of CO 2 was explored. When the intercalation ratio of pp is 3%, the performance is optimal. Compared with ZnAl LDHs, the yield of CO produced by SDS-pp(3%)/LDHs was increased by 12 times and a small amount of 8-electron reduction product CH 4 appeared. Through mechanism exploration, the matching energy level relationship between pp and LDHs promotes electron transfer from pp to LDHs. In addition, the catalyst exhibits good cyclic photocatalytic reduction performance for CO 2 due to its stable intercalation structure. [ABSTRACT FROM AUTHOR]

[Display omitted] • DQTP has a high specific surface area and narrow forbidden band width. • Anthraquinone moieties as the active sites for U(VI) photoreduction. • Photogenerated e -, •O 2 – and H 2 O 2 play the synergistic reduction mechanism. Photocatalysis can be an effective technology for the conversion of U(VI) to U(IV) because it is efficient, facile and free of secondary pollution. In this work, anthraquinone-functionalized covalent organic framework (DQTP) was fabricated by an irreversible tautomerization of 2,6-diaminoanthraquinone (DQ) and 2, 4, 6-triformylphloroglucinol (TP) in the β-ketoenamine structure. The resultant DQTP could be effectively used as a metal-free heterogeneous catalyst for the photoreduction of U(VI) (k = 0.00287 min−1). The pivotal role of anthraquinone moieties as the active sites for U(VI) reduction was evidenced, i.e., to promote charge separation and thus enhance photocatalytic activity, as well as the production of H 2 O 2 followed by the formation of (UO 2)O 2 ·2H 2 O with U(VI) through in-situ reactions. Additionally, free radical capture experiments and spectrometry analysis were conducted to determine the synergistic reduction mechanism of photogenerated electrons, superoxide radicals and hydrogen peroxide. It was reassuring that this work could provide the research basis for the subsequent development of more practical metal-free photocatalysts for the purification of U(VI)-containing wastewater. [ABSTRACT FROM AUTHOR]

The presence of oxygen vacancies and the formation of heterojunctions can effectively facilitate the adsorption of nitrogen and the subsequent hydrogenation process, which promotes the conversion of nitrogen to ammonia. [Display omitted] • Ultrathin 2D/2D heterostructures of Bi 12 O 17 Br 2 with oxygen vacancies/ZnCr layered double hydroxides (Vo-Bi 12 O 17 Br 2 /ZnCr-LDHs) is prepared. • The Vo-Bi 12 O 17 Br 2 /ZnCr-LDHs show excellent separation and transfer efficiencies of hole–electron pairs and light adsorption ability. • The existence of oxygen vacancies and formation of heterojunctions could significantly reduce the energy barrier of N 2 hydrogenation process to boost photocatalytic N 2 reduction. • The nitrogen reduction rate of the 2D/2D Vo-Bi 12 O 17 Br 2 /ZnCr-LDHs reaches 286.0 μmol·g−1·h−1. Herein, a novel ultrathin 2D/2D heterostructure, Bi 12 O 17 Br 2 with oxygen vacancies/ZnCr layered double hydroxides (V o -Bi 12 O 17 Br 2 /ZnCr-LDHs, V o -BZ) is prepared by solvothermal and coprecipitation methods for photocatalytic reduction of N 2 to NH 3. The optimal 2D/2D V o -BZ heterostructure photocatalyst shows production rate of ammonia production of 286.0 μmol·g−1·h−1. It is 12.5 and 3.6 times higher than that of pure ZnCr-LDHs and V o -Bi 12 O 17 Br 2. The improved photocatalytic nitrogen reduction performance is attributed to the intimate contact interface, matching bandgap structure, the shortened migration distance, and thus significantly improved separation and transfer efficiency of hole-electron pairs and light adsorption ability. The large number of oxygen vacancies and high specific surface promote the absorption, activation and deionization of N 2 molecules. The theoretical simulation calculation indicates that the free energy of nitrogen molecules on the surface of Vo-BZ is favorable for the absorption and activation of N 2 molecules. The existence of oxygen vacancies and formation of heterojunctions can dramatically reduce energy barrier of nitrogen molecule hydrogenation process to boost photocatalytic N 2 reduction. This study provides a new idea for the development of efficient photocatalytic nitrogen fixing catalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • Planar solid device was applied for gas-phase photoelectrocatalysis CO 2 reduction. • Heat treatment at 130 °C of GO exhibited the best CO yields under visible light. • Structure and surface properties of RGO were key factors for CO 2 reduction efficiency. • Appropriate bias improved photoelectrocatalytic performance of the device. Photoelectric co-catalysis is a promising method for carbon dioxide (CO 2) reduction due to its greater flexibility and higher reaction efficiency. However, the development of gas-phase photoelectrocatalysis is still in progress. Additionally, there is limited information available regarding the intrinsic photocatalytic capability of reduced graphene oxide (RGO) and its "structure-activity" relationship. In this study, solid planar photoelectrocatalytic (PEC) devices ITO/RGO/ITO were designed to enable gas-solid PEC CO 2 reduction. The device consists of two strip electrodes functioning as the cathode and anode, biased to create a horizontal electric field that facilitates the separation of photogenerated electron-hole pairs. RGO-130 (heat treatment at 130 °C) presented the best PEC CO 2 reduction efficiency, 2.2 times higher than photocatalysis under visible light irradiation. This enhancement can be attributed to its moderate oxygen content (48.8%), 001 crystal face and "layer upon layer" structure, all of which facilitate the separation and transfer of photogenerated carriers. Therefore, RGO is capable of acting as a stand-alone catalyst for the photocatalytic CO 2 reduction, and the appropriate design of RGO in surface and structure can improve its activity. This work provides a new perspective on research and application of PEC CO 2 reduction, in view of its environmentally safe and conducive to large-scale applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Construction of Ag/MoS 2 Ohmic contact via the photoreduction deposition. • More efficient photogenerated carriers separation achieved by Ag/MoS 2 Ohmic contact. • Higher electron concentration on MoS 2 surface boosts the photoreduction of Au(Ⅰ). • Great enhancement of gold recovery from the low concentration Au(S 2 O 3) 2 3– solution. The surface decoration of precious metal particles is one of the most effective strategies for improving the photocatalytic activity of semiconductors. In this work, a MoS 2 -based Ohmic contact was fabricated by depositing Ag nanoparticles on the surface of MoS 2 nanosheets (MoS 2 NSs) to enhance the photoreduction of Au(Ⅰ) from a low concentration Au(S 2 O 3) 2 3– solution. After the fabrication of Ohmic contact, more efficient interface charge transfer can be achieved under the drive of built-in electric field. As a result, the photogenerated singlet excitons in MoS 2 NSs are readily dissociated into free charges with the electrons drifting to Ag NPs, leading to a higher electron concentration on the surface of Ag/MoS 2 NSs. The gold recovery of Ag/MoS 2 NSs-4.15% reaches up to 96.67% for the low concentration Au(S 2 O 3) 2 3– solution, which is about 3.9 times higher than that of pristine MoS 2 NSs (24.82%). The results of this work are encouraging for further development in the surface science of photocatalysis and demonstrate a pathway for efficient gold recovery via photoreduction. [ABSTRACT FROM AUTHOR]

NiO/g-C 3 N 4 QDs composite is formed by coating g-C 3 N 4 QDs to the surface of NiO nanotubes through hydrothermal process. The absorption of the composite is enhanced by the increased interaction of incident light by multiple reflections in hollow tubes and the up-conversion photoluminescence brought by g-C 3 N 4 QDs. Benefiting from expanded light response range and the synergistic catalysis between g-C 3 N 4 QDs and NiO microtubes, the NiO/g-C 3 N 4 QDs composite realizes high performance on the photocatalytic conversion of CO 2 to CO and CH 4 under simulated solar light. [Display omitted] • Petal-like tubular NiO as photocatalyst. • Enhanced absorption caused by g-C3N4 QDs' up-conversion photoluminescence. • Synergistic catalysis between g-C 3 N 4 QDs and NiO microtubes. • Photocatalytic reduction of CO 2 to CH 4 and CO with high efficiency. Graphited C 3 N 4 quantum dots (g-C 3 N 4 QDs) exhibit an up-conversion effect, which allows them to absorb near-infrared light and emit light with a shorter wavelength. By introducing g-C 3 N 4 QDs to the surface of petal-like NiO microtubes, NiO/g-C 3 N 4 QDs composites are successfully synthesized. Various techniques have been adopted to characterize the morphology, structure, and composition of the NiO/g-C 3 N 4 QDs composites, and the interaction between NiO microtubes and g-C 3 N 4 QDs has been confirmed. The usage of sunlight by the composite materials is enhanced with the aid of the up-conversion effect of g-C 3 N 4 QDs and the novel petal-like tubular structure of NiO, which considerably improves the photocatalytic conversion of CO 2 to CH 4 and CO. When compared to NiO microtubes, the yields of CO and CH 4 on NiO/g-C 3 N 4 QDs are 2.1 and 4.2 times higher, respectively. The expanded light response range and the synergistic catalysis between g-C 3 N 4 QDs and NiO microtubes are the primary causes of the increased photocatalytic activity of CO 2 reduction on NiO/g-C 3 N 4 QDs. [ABSTRACT FROM AUTHOR]

[Display omitted] • Synthesis of 2-dimensional flaky carbon nitride with oxygen and nitrogen defects. • Catalyst has large specific surface area and efficient charge separation. • The catalysts show excellent photoactivity for CO 2 reduction. • The mechanism of photoreduction of CO 2 by catalyst was proposed. In this paper, three novel defective two-dimensional lamellar carbon nitride were successfully synthesized by molecular self-assembly using melamine and cyanuric acid as supramolecular aggregates and introducing three different uracil derivatives (5-formyluracil, 5-acetyluracil, uracil-5-carboxylic acid). In our previous work, we found that the introduction of thymine into supramolecular precursors has good photocatalytic oxidation ability for NO. On this basis, we discovered that by introducing uracil derivatives as ligands for supramolecular aggregates, not only two-dimensional porous sheet nanostructures can be constructed, but also abundant nitrogen and oxygen defects can be introduced, which is supported by various characterizations. These defects can effectively modulate the electronic structure of carbon nitride and thus improve the separation of photogenerated carriers. In addition, the introduction of uracil derivatives affects the energy band structure of the catalyst, and these are important factors affecting the catalytic activity. Compared with bulk carbon nitride, the synthesized materials exhibited significantly enhanced photocatalytic CO 2 reduction activity under mild conditions, with CO yields of 10.34, 28.65, 32.28, and 36.48 μmol g−1h−1 for BCN, CNU 2.5 , CNF 2.5 , and CNY 2.5 , respectively. More importantly, with the support of in situ DRIFTS, we proposed the reaction mechanism of photocatalytic reduction of CO. [ABSTRACT FROM AUTHOR]

Structural reorganization is developed for preparing highly polymerized ultrathin g-C 3 N 4 nanosheets, which have a great potential in visible-light-driven CO 2 photoreduction. [Display omitted] • Highly polymerized ultrathin g-C 3 N 4 nanosheets are synthesized via structural reorganization. • The bridged N-(C) 3 provides more electron transfer channels with extended conjugate π → π* system as well as distorts the plane structure with activated n → π* electronic transition. • The prepared g-C 3 N 4 shows rapid and effective photoexcited carriers transfer and separation as well as extensional visible light absorption, resulting in highly active CO 2 photoreduction in a wide spectral range. • This work offers new design ideal for highly active g-C 3 N 4 materials in visible-light‐driven CO 2 photoreduction. Graphitic carbon nitride (g-C 3 N 4) exhibits moderate CO 2 photoreduction due to fast recombination of photoexcited charges and low-grade visible light absorption. Herein, we synthesized highly polymerized ultrathin g-C 3 N 4 nanosheets by structural reorganization. Both experimental and theoretical calculations indicate that amino groups stabilized by hydrogen bonding networks are the easiest to remove to form a more stable bridged N-(C) 3. This procedure provides additional electron transfer channels with an extended conjugated π → π* system and buckled plane structure with activated n → π* electronic transitions. This new configuration significantly improves the separation efficiency of photoexcited charges and widens the light absorption range. As a result, the prepared g-C 3 N 4 shows efficient CO 2 -to-CO conversion with a CO production rate of 12.95 μmol g-1 h−1 under λ ≥ 420 visible light and 2 μmol g-1 h−1 under λ ≥ 500 visible light, respectively. This work offers a new design idea for highly active visible-light-driven g-C 3 N 4 for CO 2 photoreduction. [ABSTRACT FROM AUTHOR]

The spatial engineering of the redox-active sites controls the transfer direction of photogenerated electrons and holes, which synergistically boosts the photocatalytic CO 2 reduction to high-value hydrocarbons. [Display omitted] • The spatial separation of redox‐active sites on different facets of TiO 2 was achieved. • The mechanism of photocatalytic CO 2 reduction was revealed. • The charge transfer direction was controlled by spatial engineering of redox‐active sites. • The Cu and Co 3 O 4 sites synergistically promoted photocatalytic CO 2 reduction. Photocatalytic CO 2 reduction with H 2 O to value-added fuels is an advanced strategy to solve the energy crisis and realize carbon neutralization. Herein, the spatial engineering of redox-active sites on different facets of TiO 2 was achieved by stepwise selective photo-deposition, which controls the transfer direction of photogenerated electrons and holes. The 2Cu/TiO 2 /2Co 3 O 4 sample exhibited high photocatalytic CO 2 reduction performance with the production of CO, CH 4 , CH 3 CH 3 , and CH 2 CH 2 reached 9.41, 43.52, 5.39, and 1.41 μmol∙g cat -1∙h-1, respectively. Notably, the C 2 products was generated over the 2Cu/TiO 2 /2Co 3 O 4 composite in comparison with pure TiO 2 under same reaction condition. The in-situ DRIFTS spectra identify the formation of critical intermediates (*CHO, *CH 4 , and CHO*CHO*) and reveal the reaction kinetics of H 2 O oxidation. Moreover, the DFT calculations combined with the in-situ spectral technique are applied to investigate the reaction pathways of photocatalytic CO 2 reduction and C–C coupling. This work demonstrated that the spatial engineering of Cu and Co 3 O 4 on TiO 2 provides appropriate redox reaction sites to synergistically boost the photocatalytic CO 2 reduction and C–C coupling. [ABSTRACT FROM AUTHOR]

[Display omitted] • We designed a catalyst for the photocatalytic reduction of CO anchoring a single Ni atom on a defective hexagonal boron nitride monolayer with a B-N divacancy. • The DFT computations revealed that the synergy effect between the anchored Ni atom and its adjacent N atoms can capture multiple CO molecules. • These coupled CO species can be favorably reduced to ethanol product with a less negative limiting potential (–0.27 V). • This Ni/ d -BN catalyst can improve the visible light absorption, enabling it ideal for solar-driven conversion of CO into C 2 H 5 OH. By constructing a unique Niδ+–Nδ− atom pair, we designed a promising catalyst for the photocatalytic reduction of CO (p COR), namely, anchoring a single Ni atom on a defective hexagonal boron nitride monolayer with a B-N divacancy (Ni/ d -BN). The density functional theory (DFT) computations revealed that the synergy effect between the anchored Ni atom and its adjacent N atoms can capture multiple CO molecules, followed by their effective C–C coupling with a low kinetic barrier. Interestingly, these coupled CO species can be favorably reduced to ethanol (C 2 H 5 OH) product with a less negative limiting potential (–0.27 V), as compared with methane (CH 4 , –0.63 V), propanol (C 3 H 7 OH, –0.46 V), and the competitive hydrogen evolution reaction (HER, –0.84 V), suggesting the superior catalytic activity and the excellent selectivity of Ni/ d -BN catalyst towards p COR. Specially, this Ni/ d -BN catalyst can significantly improve the visible light absorption with a suitable band position, enabling it ideal for solar-driven conversion of CO into C 2 H 5 OH. In particular, Ni/ d -BN holds great potential for experimental synthesis due to its extremely high stability. Our findings not only open a new avenue to solve the problems of the high energy-consumption in FTS, but also offer a tandem strategy for CO 2 conversion to multi-carbon products. [ABSTRACT FROM AUTHOR]

The adsorption configuration of CO 2 on the catalysts changed from monodentate to bidentate after the introduction of bridging oxygen vacancies into SnTa 2 O 6 , which is beneficial for CO 2 adsorption and activation. The good stability of SnTa 2 O 6−x can be attributed to the distinct molecular configuration of CO 2 , which avoids filling and consuming of the oxygen vacancies. [Display omitted] • The bridging oxygen vacancies were constructed in SnTa 2 O 6−x by an improved flame reduction method. • 40-SnTa 2 O 6−x showed 7.5 times improved visible light catalytic activity with a CO yield of 21.1 μmol h−1 g−1. • The transition of adsorption configuration of CO 2 on the catalysts boosts adsorption and activation. • The bidentate configuration avoids filling of oxygen vacancies and ensures its stability. Construction of oxygen vacancies is a common strategy to improve the performance of metal oxide photocatalysts. However, the oxygen vacancies can be easily filled and consumed by the oxygen atoms of CO 2 molecules during CO 2 photoreduction reactions, resulting in deactivation of the catalyst. In this study, bridging oxygen vacancies were introduced into SnTa 2 O 6 nanosheets, which remarkably enhanced the photocatalytic performance with good stability. The SnTa 2 O 6−x obtained after 40 s of flame reduction treatment showed 7.5 times higher visible-light-activity than pristine SnTa 2 O 6 (21.1 μmol h−1 g−1 of CO), and sustained good stability even after five cycles. Accompanied by a positive shift in the d-band center, the adsorption configuration of CO 2 on the catalysts changed from monodentate to bidentate after the introduction of bridging oxygen vacancies into SnTa 2 O 6 , which is beneficial for CO 2 adsorption and activation. Furthermore, the bridging oxygen vacancies in SnTa 2 O 6−x can reduce the Gibbs free energy of COOH*, and facilitate the photo conversion of CO 2 by receiving photogenerated electrons. The good stability of SnTa 2 O 6−x can be attributed to the distinct molecular configuration of CO 2 , which avoids filling and consuming the oxygen vacancies. [ABSTRACT FROM AUTHOR]

A ternary ZnIn 2 S 4 @TiO 2 /Ti 3 C 2 Z-scheme heterostructure was successfully fabricated using the hydrothermal method. The synthesized heterostructure shows excellent photocatalytic CO 2 reduction activity and stability for the production of CO and CH 4. [Display omitted] • ZnIn 2 S 4 @TiO 2 /Ti 3 C 2 heterostructures were fabricated via the hydrothermal approach. • The ternary heterostructure exhibits excellent CO 2 photoreduction and stability. • The synergy between ZnIn 2 S 4 and TiO 2 /Ti 3 C 2 enhanced charge transfer efficiency. • The ZnIn 2 S 4 @TiO 2 /Ti 3 C 2 ternary heterostructure Z-Scheme mechanism was elucidated. The low carbon dioxide (CO 2) conversion efficiency of semiconductor heterojunction-based photocatalysts is a lingering issue in the field of solar energy-driven catalysis. In this study, sandwich-like hierarchical heterostructures of two-dimensional (2D) ultrathin ZnIn 2 S 4 nanosheets and octahedral titanium dioxide (TiO 2) nanoparticles were grown in situ on Ti 3 C 2 MXene via a hydrothermal method. Significantly, the ZnIn 2 S 4 @TiO 2 /Ti 3 C 2 ternary heterostructure shows better CO 2 reduction activity and the optimal catalyst has carbon monoxide (CO) and methane (CH 4) production rates of 59.8 and 23.44 μmol g−1, respectively, within 8 h of simulated solar light illumination, which was greater than that pristine ZnIn 2 S 4. These ultrathin ZnIn 2 S 4 nanosheets and TiO 2 /Ti 3 C 2 Schottky-junctions assisted the heterostructures to reduce photogenerated electron–hole recombination and increase photogenerated charge-transfer and separation in a Z-scheme pathway. ZnIn 2 S 4 @TiO 2 /Ti 3 C 2 heterostructure photocatalysts have superior photocatalytic CO 2 conversion and good stability compared to pure ZnIn 2 S 4. Thus, the suggested approach is to design a highly-efficient photocatalyst for environmental remediation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cu-TiO 2 NFs/MoSe 2 heterojunctions were fabricated through the solvothermal method for the UV–vis light active photocatalytic CO 2 reduction. • Integration of copper coupled with a highly conductive phase of 1 T MoSe 2 (80%) accelerated the separation and migration of photogenerated carriers. • Reaction intermediates are directly detected and analyzed by in-situ FTIR spectra. • A 2 wt% MoSe 2 loaded on one-dimensional Cu-doped TiO 2 showed the highest CO 2 photoreduction activity (H 2 ; 81 µmol/g, CO; 396 µmol/g, and CH 4 ; 92 µmol/g) with CO 2 selectivity of 90%. • A possible S-scheme mechanism for CO 2 photoreduction over Cu-TiO 2 NFs/MoSe 2 was proposed. Efficient solar-driven conversion of CO 2 into valuable chemical energy offers a promising way to address the issues of energy shortage and climate change. However, the weak and slow charge kinetics severely impede CO 2 photoreduction. Herein, hybrid-phase MoSe 2 (1 T-2H MoSe 2) nanosheet-coated Cu-doped TiO 2 nanofibers (Cu-TiO 2 NFs) were prepared using a solvothermal method. Different characterizations confirmed the successful doping of Cu into a TiO 2 crystal lattice and the generation of stable 1 T-2H MoSe 2 in the composite samples. The developed internal electric field drives electrons from the Cu-TiO 2 NFs to MoSe 2 , demonstrating the presence of a Step-scheme (S-scheme) charge transfer path in the Cu-TiO 2 NFs/1T-2H MoSe 2 heterostructure, which allows efficient and selective CO 2 photoreduction. In addition, the optimum sample contains an abundant 1 T MoSe 2 coupled with Cu+/Cu0 which offers copious active sites to improve CO 2 adsorption and subsequent conversion to CO and CH 4. The optimum sample exhibits a remarkable CO 2 selectivity of 90%. These findings provide new possibilities for improving the preparation of efficient photocatalysts for the photoreduction of CO 2. [ABSTRACT FROM AUTHOR]

The electrical transport processes of zinc telluride (ZnTe) uniformly dispersed in reduced graphene oxide matrix (RGO-ZnTe composite) were investigated. It is observed from DC measurements that the charge transport process is consistent with Mott three dimensional variable range hopping (3D-VRH) in 85 K–280 K, confirmed by resistance curve derivative analysis (RCDA) method. AC conductivity indicates a Debye-like relaxation process caused by quantum mechanical tunneling (QMT) between localized sites in 90 K–473 K range. Magnetization data of RGO-ZnTe composite from SQUID and electron paramagnetic resonance (EPR) spectra show paramagnetic behaviour in 5 K–330 K despite the diamagnetism of pure RGO and ZnTe at room temperature. In photosensitivity, one order enhancement was observed in the RGO-ZnTe composite alongside three times higher reduction rate constant in photoreduction of aqueous pollutant 4-nitrophenol as compared to pure ZnTe. These significant increases in photocurrent and photoreduction efficiencies are attributed to dispersion of ZnTe on the 2D RGO surface indicating the synergy of ZnTe nanoparticle with RGO sheets. • DC conductivity reveals a conduction mechanism consistent with Mott three dimensional variable range hopping (3D-VRH) of charge carriers in 85 K–280 K. • DC measurement shows a crossover of charge transport mechanism from 3D-VRH (85 K–280 K) to Arrhenius behaviour (290 K–473 K). • AC conductivity suggests a Debye-like relaxation process caused by quantum mechanical tunneling (QMT) between localized states in 90 K–473 K. • RGO-ZnTe composite shows paramagnetic behaviour despite the diamagnetism in pure RGO and ZnTe. • One order enhancement of photosensitivity and three times improved photocatalytic reduction rate constant point to potential applications of RGO-ZnTe in optoelectronic device fabrication. [ABSTRACT FROM AUTHOR]

A novel catalytic material of MOF-based In 2 S 3 -X 2 S 3 (X = Bi; Sb)@TFPT-COFs hybrids was designed and synthesized by using an interface ion-exchange method with MOFs as the precursors. The hybrid materials were fabricated by combining heterojunctions with TFPT-COFs through C N bonds. The functionalization of the amino groups on the heterojunction surface was a crucial step to construct the MOFs@COFs hybrid materials. The resulting samples were hierarchical tubular nanostructures with uniform nano-scale interfacial contacts. The doping of Bi3+ or Sb3+ further facilitated the construction of heterojunctions to reduce the band gap value of In 2 S 3 and extended light absorption range. The synergistic effect between the frameworks contained in In 2 S 3 -X 2 S 3 (X = Bi; Sb) and the triazine frameworks of TFPT-COFs was conducive to accelerating charge transportation and separation. The photo-erosion of heterojunctions could also be prevented by the encapsulated TFPT-COFs sheets. Noteworthily, the photocatalytic degradation abilities of hexavalent chromium, ponceau-4R and rhodamine B were significantly improved after the introduction of TFPT-COFs. Especially, In 2 S 3 -Sb 2 S 3 @TFPT-COFs performed excellent photocatalytic reduction activity. Approximately 100% of aqueous Cr(VI) was photo-reduced within only 5 min. Based on the experimental results of UV–Vis adsorption spectra and ESR spectra, a possible mechanism was proposed to explain the excellent photocatalytic performance of the photocatalytic system. Unlabelled Image • MOF-based In 2 S 3 -X 2 S 3 (X = Bi; Sb)@TFPT-COFs composites were synthesized by interface design. • The hybrid materials presented well-defined hierarchical hollow structures. • Doping of Bi3+, Sb3+ reduced the band gap of In 2 S 3 and extended light absorption range. • The hybrid materials exhibited efficient photodegradation of Cr(VI), Ponceau-4R, and RhB. • Excellent photocatalytic activity was performed due to the synergistic effect of the framework. [ABSTRACT FROM AUTHOR]

Three TiO 2 and Zn-Al-layered double hydroxide composites, denoted LDH-TiO 2 composites, were prepared using the sol–gel method and characterized utilizing scanning and transmission electron microscopy with energy dispersive spectroscopy, ultraviolet–visible diffuse reflectance spectroscopy, X-ray diffraction, N 2 adsorption–desorption, X-ray photoelectron spectroscopy, photocurrent, photoluminescence and electrochemical impedance spectroscopy techniques. The characterization results illustrated that TiO 2 was attached onto the surface of LDH and the sizes of both TiO 2 and LDH particles were in the nanoscale range. The combination of LDH and TiO 2 promoted the photogenerated electron–hole transfer and separation. The removal abilities of the LDH-TiO 2 composites for Cr(VI) were evaluated using the synergistic adsorption and photocatalytic method. The adsorption percentages of the three LDH-TiO 2 composites for 20.0 mg/L Cr(VI) solutions ranged between 26% and 75%, and upon ultraviolet irradiation, the total removal percentages rapidly increased to approximately 100%. The removal efficiency for Cr(VI) depended on the TiO 2 contents of the LDH-TiO 2 composites. Increasing the TiO 2 percentage resulted in decrease in the adsorption capacities and increase in the photocatalytic removal ratios. The kinetic and isothermal data well fitted the pseudo-second-order and Langmuir equations, respectively. The high removal efficiencies suggested that the composites were suitable for the treatment of Cr(VI)-containing wastewater. Unlabelled Image • The removal percentage of LDH-TiO 2 composites for 20 mg/L Cr(VI) approached 100%. • The combination of Zn-Al-LDH and TiO 2 promoted photoinduced charge transport. • Cr(VI) was removed using LDH-TiO 2 via synergistic adsorption and photocatalysis. [ABSTRACT FROM AUTHOR]

In this work, an in-situ way has been developed to achieve the co-modification of highly-dispersed Mn and Cu oxides to g-C 3 N 4 nanosheets for efficient CO 2 reduction. The Mn & Cu amount-optimized nanosheets exhibit the improved photocatalytic activity for CO 2 reduction to CO and CH 4 both by 3 times compared with the generally-bulk g-C 3 N 4 , mainly attributed to the nanosheet structure and to the roles of modified Mn and Cu oxides. Based on the transient-state surface photovoltage responses, transient-state photoluminescence spectra, and electrochemical measurements, it is confirmed that the modified Mn and Cu oxides could respectively capture the photogenerated holes and electrons, and provide the catalytic functions for water oxidation and CO 2 reduction. Remarkably, the simultaneous introduction of Mn and Cu oxides shows an obvious synergistic effect on the improvement of photocatalytic activity for CO 2 reduction. This work provides a feasible way to synthesize high-activity g-C 3 N 4 -based photocatalysts for energy production. Photoactivities for CO 2 conversion of g-C 3 N 4 are enhanced after co-modifying MnO x and CuO x , attributed to their roles of modulating charges and providing catalytic functions. Unlabelled Image • A supramolecular preorganization method is developed to achieve in-situ co-modification of Mn and Cu oxides to g-C 3 N 4. • Optimized g-C 3 N 4 exhibits improved photoactivity, attributed to nanosheet structure and to modifier roles. • Modified MnO x could capture photogenerated holes and provide catalytic functions for water oxidation. • Modified CuO x could capture photogenerated electrons and provide catalytic functions for CO 2 reduction. • There is a synergetic effect between modulating photogenerated electrons and holes on improved photoactivity. [ABSTRACT FROM AUTHOR]

Constructing Bi-rich photocatalysts has been regarded as a promising strategy for promoting the photocatalytic performance of bismuth oxyhalides, however, tailored fabrication of Bi-rich bismuth oxyhalides with hierarchical structure still remains unexplored. Hereof, Bi 24 O 31 Br 10 hierarchical hexagonal nanoplates (HPs) are fabricated via facile co-precipitation with subsequent hydrothermal (solvothermal) treatment. The ethylene glycol coordination induced dissolving-recrystallization of one-dimensional Bi 24 O 31 Br 10 nanobelts (NBs) gives rise to the construction of such unique hierarchical structure. Attributed to the compact intersecting and stacking of nanosheets in this hierarchical structure, Bi 24 O 31 Br 10 HPs are rich in interfaces relative to Bi 24 O 31 Br 10 hierarchical flowers (HFs) constructed by sparsely assembled nanosheets. The abundant interfaces endow hierarchical structure with enhanced charge storage ability for suppressing rapid electron-hole recombination, leading to facilitated separation of photogenerated charge carriers. Thanks to this advantage, Bi 24 O 31 Br 10 HPs display standout catalytic properties in comparison with Bi 24 O 31 Br 10 HFs with fewer interfaces and Bi 24 O 31 Br 10 NBs without hierarchical structure, which only need 20 min and 30 min to reduce 94% of Cr(VI) and degradation of 90% OTC under visible light illumination, respectively. This work not only presents the first report about the fabrication of Bi 24 O 31 Br 10 hierarchical hexagonal nanoplates, but also discloses the pivotal role of interfaces in boosting the photocatalytic performance of hierarchical photocatalysts. • Tailored fabrication of interface-rich Bi 24 O 31 Br 10 hierarchical hexagonal nanoplates. • Storage electrical charge at interfaces for photoinduced carriers separation. • Bi 24 O 31 Br 10 HPs exhibits improved photocatalytic performance for reduction of Cr(VI). [ABSTRACT FROM AUTHOR]

Novel hybrid decontamination processes based on visible-light-responsive photocatalysts (VLPHS) have recently become a focus of environmental research. In this study, the sonophotocatalytic degradation of the antibiotic tetracycline (TC) using a binary rGO/CdWO 4 composite under simulated visible-light irradiation was demonstrated for the first time. Structural characterization confirmed that flower-like CdWO 4 particles with a wolframite phase structure were successfully immobilized on the surface of the graphene oxide (GO). Subsequently, reduced GO/CdWO 4 (rGO/CdWO 4) VLPHS were prepared via the facile photocatalytic reduction of GO/CdWO 4. A Box-Behnken design based on response surface methodology (RSM) was employed to determine the maximum efficiency of sonophotocatalytic degradation by optimizing the process parameters (pH, initial TC concentration, treatment time, and catalyst dosage). The high determination coefficients (R 2 = 0.9818 and adjusted- R 2 = 0.9636) indicated that the experimental values fitted the proposed RSM model well. Compared with CdWO 4, rGO/CdWO 4 VLPHS exhibited significant photoelectrochemical (PEC) performance, superior sonophotocatalytic activity, and mineralization efficiency. The enhanced catalytic activity was mainly due to the larger optical adsorption range, greater photo-induced charge carrier transfer, and higher surface area. In addition, rGO/CdWO 4 exhibited a catalytic activity that was 1.5 and 3 times higher than that of commercial nano–ZnO and –TiO 2 , respectively. The kinetic analysis indicated that the degradation rate of TC follows the Langmuir–Hinshelwood kinetic model. The possible photocatalytic mechanism behind the degradation of TC by rGO/CdWO 4 was also tentatively proposed. This study provides a simple and scalable pathway to produce highly efficient rGO-based VLPHS for photocatalytic and PEC applications. Unlabelled Image • Facile wet chemistry is reported for the synthesis of rGO/CdWO 4 photocatalysts. • Tetracycline (TC) completely degraded by sonophotocatalysis. • rGO/CdWO 4 exhibits superior sonophotocatalytic activity over nano-ZnO and nano-TiO 2. • Maintaining the high sonophotocatalytic activity after four cycles of reusability tests • Sonophotocatalytic mechanism for degradation of TC over rGO/CdWO 4 was proposed. [ABSTRACT FROM AUTHOR]

Highly efficient visible-NIR photocatalytic activity of Ag-RGO@{010}BiVO 4 /RGO@{110}BiVO 4 photocatalysts are successfully synthesized via an in situ photoreduction method. The transverse electric TE mode accompanied by surface plasmon collective excitations of RGO compel photocatalyst to absorb NIR light. Significantly, the degradation rate of 15%Ag-RGO@{010}BiVO 4 /RGO@{110}BiVO 4 photocatalysts can reach the highest 98.3% and 66.1%, and the mineralization yield can reach to 97.22% and 74.25% within 90 min under visible and 180 min NIR irradiation, respectively. The extraordinary visible and NIR photocatalytic activity is attributed to resonance effect of local electric field formed by transverse electric TE mode of RGO and local magnetic field formed by transverse magnetic TM of plasmonic Ag can accelerate carrier separation, and energetic carriers induce by SPR effect of plasmonic Ag nanoparticles can directly oxidize organic pollutants to small molecules. The as-synthesized Ag-RGO@{010}BiVO 4 /RGO@{110}BiVO 4 hybrid photocatalysts exhibit excellent wide-spectrum response to wavelengths ranging from visible to near-infrared (NIR), indicating its potential for effective utilization of solar energy. • Highly NIR photocatalytic activity of Ag-BiVO 4 @RGO photocatalysts were synthesized by in situ photoreduction method. • The transverse electric mode formed by RGO compel Ag-BiVO 4 @RGO hybrid photocatalyst to absorb NIR light. • The optimal performance is due to the resonance effect of local electric field of RGO and local magnetic field of Ag. [ABSTRACT FROM AUTHOR]

Well-designed 1D/2D composite, consisting of carbon nanotubes modified protonated carbon nitrides (CNTs/pCN) embedded with Cu-NPs were synthesized by a facile sonicated assisted chemical method. The performance of catalysts towards dynamic CO 2 reduction to selective fuels was conducted under UV/visible light irradiations in a continuous flow photoreactor. Photo-activity of g-C 3 N 4 for CO production was increased by 2.38 folds after surface charge modification due to faster charge carrier separation. Loading 3 wt% Cu and 0.5 wt% CNTs into pCN gave highest activity for the production of CO, CH 4 and CH 3 OH under visible light. The highest CO yield as the main product over Cu-CNTs/pCN composite was 560 μmole g-cat−1 h−1, a 1.21, 1.36, 3.78 and 9.03 folds higher than using Cu/pCN, CNTs/pCN, pCN and g-C 3 N 4 samples, respectively. This significantly enhanced photo-activity can be attributed to visible light absorption and multi-stage charges separation in the presence of Cu/CNTs. More interestingly, CO obtained under visible light was 4 times higher than using UV-light, while performance for CH 4 production was 14 folds higher with visible light than using UV-light under the same operating conditions. Among the different catalyst loadings, 150 mg gave highest productivity, evidently due to limitations in exposed catalyst active surface area. Additionally, Cu-CNTs/pCN photocatalyst prevailed excellent stability in cyclic runs for continuous CO 2 reduction. The findings of this work would be attractive for the development of CO 2 conversion systems with renewable fuels production under solar energy. Unlabelled Image • Well-designed 1D/2D CNTs/g-C 3 N 4 heterojunction tested for CO 2 conversion to fuels. • Cu-MWCNTs/pCN hybrid yielded CO, CH 4 and CH 3 OH under UV and Visible light. • Yield of CO over Cu-CNTs/pCN was 9 folds higher than using g-C 3 N 4 under visible light. • Synergistic effect of Cu/CNTs promoted g-C 3 N 4 activity for CO 2 conversion to CO. • Cu-CNTs/pCN prevailed stability in cyclic-runs for CO/CH 4 evolution under visible light. [ABSTRACT FROM AUTHOR]

Photocatalytic conversion of carbon dioxide to valuable chemicals by using semiconductor materials is one of the major challenges in materials science. Higher efficiency and product yield can be achieved by designing of a suitable photocatalyst with retarded recombination of photogenerated electron-hole pair and sufficient potential for the reduction of CO 2. In this work, unique composite architecture of graphene-oxide wrapped TiO 2 nanotubes for the photocatalytic reduction of CO 2 has been developed. The TiO 2 nanotubes formed by electrochemical anodization are wrapped with graphene oxide/reduced graphene oxide (GO/rGO) layers which also form interconnecting bridges between the adjacent nanotubes. Such a unique nanostructure helped the separation of photogenerated electron-hole pairs with better charge transfer to perform the reduction of adsorbed CO 2 molecules. The rGO/TiO 2 multi-leg nanotubes (MLNTs) have shown the highest photocatalytic activity with maximum yield of CO c.a. 1348 μmol g−1 within the first 20 min, which stabilize to about 760 μmol g−1 after 2 h of UV-A irradiation. More importantly, the CO formation rate is about an order of magnitude higher than that from graphene supported TiO 2 nanocrystals. Unlabelled Image • A unique nanostructure in the form of graphene oxide wrapped TiO 2 nanotubes have been used to carry out photocatalytic CO 2 reduction • Detailed 'blank' experiments confirmed the product formation is solely from feed gas CO 2 and not due to decomposition of graphene oxide • Selective CO formation is obtained with values about an order of magnitude higher that the previously reported data. [ABSTRACT FROM AUTHOR]

[Display omitted] The current energy shortage is a cause for concern and nuclear energy is an important sustainable energy source that is vital to the energy transition. As an important resource for the nuclear industry, uranium is present in large quantities in seawater. However, the efficient extraction of uranium from seawater remains challenging due to low uranium concentrations and biofouling. In this work, 2D-perylene diimide-polyethyleneimine (PDI-PEI) photocatalyst have been successfully synthesised by cross-linking polyethyleneimine on the surface of perylene diimide, which enhanced the extraction of uranium from seawater. An electric field is formed on the surface of the material by photocatalysis, where the positively charged part attracts the negatively charged uranyl group, facilitating the adsorption of uranium to the material. The electrons generated on the surface reduce the adsorbed U(VI) to the insoluble U(IV) and can achieve over 99% removal of uranium in solution. In addition, the PDI-PEI exhibited high antibacterial activity to the bacteria by producing reactive oxygen species. In summary, PDI-PEI have good photocatalytic activity, antimicrobial properties and hydrophilicity, which enhance the ability of the material to extract uranium from seawater and provide a versatile method to enhance uranium adsorption. [ABSTRACT FROM AUTHOR]

We report an in situ constructed Mo@MoO 3 Schottky junction and investigate its synergistic interaction with oxygen vacancies for efficient N 2 photoreduction, where the Schottky junction forms a charge transfer channel during the photocatalytic reaction. The oxygen vacancies, while capturing electrons to activate N 2 , together with the Mo element, expand the light absorption range of the catalyst, allowing more efficient transfer of excited electrons to the active site for nitrogen fixation. [Display omitted] • In-situ construction of Mo@MoO 3 Schottky junctions. • Photocatalytic nitrogen fixation by synergistic interaction of Schottky junctions and oxygen vacancies. • Nanosheets of Mo@MoO 3 are more conducive to the rapid transfer of photogenerated electrons in photocatalytic reactions. Defect engineering is a promising technique that can activate nitrogen by injecting electrons into the anti-bonding molecular orbital of nitrogen through anion vacancies. Moreover, compared to a single component, Schottky junctions can effectively overcome rapid electron recombination, thereby significantly enhancing photoelectron utilization efficiency. In this work, we prepared Mo modified MoO 3 nanosheets with abundant oxygen vacancies by a solvothermal method and investigated the effect of synergistic interactions between Schottky junctions and oxygen vacancies on the photocatalytic performance of N 2 reduction reaction (NRR). The photocatalytic nitrogen fixation performance of Mo@MoO 3 nanosheets (MoO 3 -6) reached 50.78 μmol·g−1·h−1 without any scavenger, which was about 3 times that of commercial MoO 3. The Schottky barrier creates a built-in electric field generating charge transfer channels during the photocatalytic reaction, while the oxygen vacancies trap electrons to activate N 2 , and together with Mo, broaden the light absorption range of the catalyst, facilitating more efficient transfer of excited electrons to the active site. The synergetic advantages of Schottky junctions and oxygen vacancies are exploited in advancing the photocatalytic effect, providing new opportunities and challenges for the development of metal oxide-based materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ag and Pd are anchored on SrBi 2 Ta 2 O 9 to construct CO and CH 4 evolution sites. • Ag and Pd attract and accumulate the electrons originating from SrBi 2 Ta 2 O 9. • The intermediate species CO* desorb and form CO directly on the surface of Ag. • The CO* is further hydrogenated to form CH 4 on the surface of Pd. Photocatalytic CO 2 reduction in presence of H 2 O provides an ideal way to alleviate the greenhouse effect and obtain valuable chemicals. Constructing active sites on the surface of photocatalysts significantly affects the activity and selectivity of photocatalytic CO 2 reduction, which involves a multi-electron reduction process. Herein, we anchor Ag and Pd particles on the surface of layered perovskite SrBi 2 Ta 2 O 9 to build CO and CH 4 evolution sites, respectively, via a photodeposition method. Ag and Pd not only attract and accumulate the photoinduced electrons originating from SrBi 2 Ta 2 O 9 due to the formed Schottky junction between them, but also activate CO 2 molecules, thereby resulting in higher CO 2 reduction activity. On the surface of Ag, intermediate species CO* desorb and form CO directly, whereas, on the surface of Pd, intermediate species CO* is further hydrogenated to form CH 4 , thus resulting in different selectivity. This work offers a new avenue for developing photocatalysts with high activity and selectivity for CO 2 reduction. [ABSTRACT FROM AUTHOR]

[Display omitted] • In 2 S 3 /Zn 0.3 Cd 0.7 S heterojunction with anionic and cationic defects. • Photocatalytic gas reduction and organic synthesis simultaneously carrying out. • The products of photocatalytic CO 2 reduction monitoring by in-suit FTIR method. • The revelation of kinetic process and rate-determining step for CO 2 reduction. Defect engineering is a highly effective approach to regulate the electronic structure of the catalyst surface, widely employed in the field of photocatalytic energy conversion. In this study, we have successfully synthesized a novel dual-defective In 2 S 3 /Zn 0.3 Cd 0.7 S (IS/ZCS) heterojunction structure via a self-assembly method, composed of Zn-vacancy-rich Zn 0.3 Cd 0.7 S (ZCS) and S-vacancy-rich In 2 S 3 (IS). Under visible light illumination, 3% IS/ZCS sample exhibits remarkable photocatalytic performance in the synergistic reaction of CO 2 reduction and 4-chlorobenzyl alcohol (Cl-PhCH 2 OH) oxidation with the CO yield significantly improved by a factor of 3.5 and 51 compared to that of ZCS and IS, respectively. The combined experimental data and theoretical calculations demonstrate that the dual-defective structure and Z-scheme transfer mode are the key factors behind the enhanced photocatalytic activity, providing more active sites and effectively improving the utilization of photogenerated charge carriers (PCCs). Moreover, the reaction pathway and catalytic mechanism of photocatalytic CO 2 reduction were elucidated by the in-situ FTIR technique combined with DFT calculations, monitoring the intermediate and final products during the reaction period. Our results provide a powerful example of designing novel heterojunction photocatalysts with high activity and accelerating the separation of PCCs, with broad implications for the development of efficient photocatalytic systems. [ABSTRACT FROM AUTHOR]