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Taking into account the electron-rich and visible light response of thiophene, first-principles calculations have been carried out to explore the photocatalytic activity of donor–acceptor polymers incorporating thiophene and boron. Honeycomb-kagome boron–thiophene (BTP) polymers with varying numbers of thiophene units and fixed B center atoms are direct bandgap semiconductors with tunable bandgaps ranging from 2.41 to 1.88 eV and show high absorption coefficients under the ultraviolet and visible regions of the solar spectrum. Fine-tuning the band edges of the BTP polymer is efficiently achieved by adjusting the pore size through the manipulation of thiophene units between the B centers. This manipulation, achieved without excessive chemical functionalization, facilitates the generation of an appropriate quantity of photoexcited electrons and/or holes to straddle the redox potential of the water. Our study demonstrates that two units between B centers of thiophene in BTP polymers enable overall photocatalytic water splitting, whereas BTP polymers with larger pores solely promote photocatalytic hydrogen reduction. Moreover, the thermodynamics of hydrogen and oxygen reduction reactions either proceed spontaneously or need small additional external biases. Our findings provide the rationale for designing metal-free and single-material polymer photocatalysts based on thiophene, specifically for achieving efficient overall water splitting. [ABSTRACT FROM AUTHOR]

The immobilization of Re(I) complexes onto metal oxide surfaces presents an elegant strategy to enhance their stability and reusability toward photocatalytic CO2 reduction. In this study, the photocatalytic performance of fac-[ClRe(CO)3(dcbH2)], where dcbH2 = 4,4′-dicarboxylic acid-2,2′-bipyridine, anchored onto the surface of 1%m/m CuO/Nb2O5 was investigated. Following adsorption, the turnover number for CO production (TONCO) in DMF/TEOA increased significantly, from ten in solution to 370 under visible light irradiation, surpassing the TONCO observed for the complex onto pristine Nb2O5 or CuO surfaces. The CuO/Nb2O5 heterostructure allows for efficient electron injection by the Re(I) center, promoting efficient charge separation. At same time CuO clusters introduce a new absorption band above 550 nm that contributes for the photoreduction of the reaction intermediates, leading to a more efficient CO evolution and minimization of side reactions. [ABSTRACT FROM AUTHOR]

In-situ polymer capping of cesium lead bromide (CsPbBr3) nanocrystals with polymethyl acrylate is an effective approach to improve the colloidal stability in the polar medium and thus extends their use in photocatalysis. The photoinduced electron transfer properties of polymethyl acrylate (PMA)-capped CsPbBr3 nanocrystals have been probed using surface-bound viologen molecules with different alkyl chains as electron acceptors. The apparent association constant (Kapp) obtained for the binding of viologen molecules with PMA-capped CsPbBr3 was 2.3 × 107 M−1, which is an order of magnitude greater than that obtained with oleic acid/oleylamine-capped CsPbBr3. Although the length of the alkyl chain of the viologen molecule did not show any impact on the electron transfer rate constant, it influenced the charge separation efficiency and net electron transfer quantum yield. Viologen moieties with a shorter alkyl chain length exhibited a charge separation efficiency of 72% compared with 50% for the longer chain alkyl chain length viologens. Implications of polymer-capped CsPbBr3 perovskite nanocrystals for carrying out photocatalytic reduction in the polar medium are discussed. [ABSTRACT FROM AUTHOR]

Photocatalytic reduction of CO2 is a promising strategy to mitigate the effects of global warming by converting CO2 into valuable energy‐dense products. Silver bismuth iodide (SBI) is an attractive material owing to its tunable bandgap and favorable band‐edge positions for efficient CO2 photoreduction. In this study, SBI materials, including AgBi2I7, AgBiI4, Ag2BiI5, and Ag3BiI6 are first synthesized, through gas‐solid reaction by controlling the stoichiometric ratio of reactants. The X‐ray absorption near edge structure (XANES) and extended X‐ray absorption fine structure (EXAFS) results revealed that the distance between Ag‐I is proportional to the degree of Ag ions delocalization, which occupies the vacant sites. That greatly retards the charge recombination at vacant sites. In addition, the surface potential via photo‐assisted Kelvin probe force measurements of various SBI catalysts shows that Ag3BiI6 exhibits the highest surface potential change due to the rich delocalized Ag ions. This results in effective charge carrier transport and prevention of charge recombination at vacant sites. Taking the above advantages, the averaged CO and CH4 production rates for Ag3BiI6 achieved 0.23 and 0.10 µmol g−1 h−1, respectively. The findings suggest that Ag3BiI6 has a high potential as a novel photocatalyst for CO2 reduction and sheds light on the possibility of solving environmental contamination and sustainable energy crises. [ABSTRACT FROM AUTHOR]

The synthesis and characterization of porphyrin center regulated three‐dimensional covalent organic frameworks (COFs) with 2‐fold interpenetrated scu or sqc topology have been investigated. These COFs exhibit unique structural features and properties, making them promising candidates for photocatalytic applications in CO2 reduction and artemisinin synthesis. The porphyrin center serves as an anchor for metal ions, allowing precise control over structures and functions of the frameworks. Furthermore, the metal coordination within the framework imparts desirable catalytic properties, enabling their potential use in photocatalytic reactions. Overall, these porphyrin center regulated metal‐controlled COFs offer exciting opportunities for the development of advanced materials with tailored functionalities. [ABSTRACT FROM AUTHOR]

The synthesis and characterization of porphyrin center regulated three‐dimensional covalent organic frameworks (COFs) with 2‐fold interpenetrated scu or sqc topology have been investigated. These COFs exhibit unique structural features and properties, making them promising candidates for photocatalytic applications in CO2 reduction and artemisinin synthesis. The porphyrin center serves as an anchor for metal ions, allowing precise control over structures and functions of the frameworks. Furthermore, the metal coordination within the framework imparts desirable catalytic properties, enabling their potential use in photocatalytic reactions. Overall, these porphyrin center regulated metal‐controlled COFs offer exciting opportunities for the development of advanced materials with tailored functionalities. [ABSTRACT FROM AUTHOR]

Herein we studied visible-light-driven CO2 reduction using a series of tetra-phenylporphyrin iron catalysts and inexpensive anthraquinone dyes. Varying the functional groups on the phenyl moieties of the catalysts significantly enhances the photocatalytic activity, achieving an optimal turnover number (TON) of 10 476 and a selectivity of 100% in the noble-metal-free systems. The highest activity found in a bromo-substituted catalyst is attributed to favorable electron transfer from the photosensitizer to the iron porphyrin. [ABSTRACT FROM AUTHOR]

Herein, we present a dark-green crystalline tetranuclear Cu(II) Schiff base complex {C1 = [Cu4L4](ClO4)4(DMF)4(H2O)} using a N,N,O donor ligand (HL), namely 2-(((2-hydroxypropyl)imino)methyl)-6-methoxyphenol. Spectro-photometrical investigation on the β-lactamase-like activity of this coordinately saturated system revealed its catalytic inefficiency towards hydrolysis of nitrocefin as a model substrate. This complex has attracted significant interest as a promising photo-catalyst owing to its narrow band gap (2.40 eV) as predicted from DFT calculations and its higher responsivity towards UV light. Therefore, C1 is effectively involved in the photocatalytic reduction of perchlorate to Cl− in the presence of a hole scavenger (H2O–MeOH) under prolonged UV irradiation and itself becomes photo-cleaved to yield a new dark-brown colored chlorobridged dinuclear crystalline complex C2 {[CuL(H2O)2Cl3]H2O}. Furthermore, C2 was deployed as a functional β-lactamase model and was found to show a remarkable catalytic proficiency towards the hydrolysis of nitrocefin in 70 : 30 (V/V) MeOH–H2O medium. This pro-catalyst C2 has been speculated to generate an aqua bridged active catalyst that plays a crucial factor in hydrolysis. This phenomenon was again experimentally established by potentiometric pH titration where C2 displays only one pKa value (7.11) in the basic pH range, indicating the deprotonation of the bridged water molecule. Based on several other kinetic studies, it may be postulated that the hydrolysis of nitrocefin is initiated by the nucleophilic attack of a bridging hydroxide, followed by very fast protonation of the intermediate to furnish the hydrolyzed product. It is noteworthy that the rate of nitrocefin hydrolysis is greatly inhibited in the presence of external chloride concentration. To the best of our knowledge, this is the first report on the photochemical behavior of such a tetranuclear copper(II) Schiff base complex. Our current interest is focused on inventing a potent β-lactamase inhibitory therapeutic as well as elucidating its mechanism through comprehensive chemical analysis. [ABSTRACT FROM AUTHOR]

In the design of photoelectrocatalytic cells, a key element is effective photogeneration of electron‐hole pairs to drive redox activation of catalysts. Despite recent progress in photoelectrocatalysis, experimental realization of a high‐performance photocathode for multi‐electron reduction of chemicals, such as nitrate reduction to ammonia, has remained a challenge due to difficulty in obtaining efficient electrode configurations for extraction of high‐throughput electrons from absorbed photons. This work describes a new design for catalytic photoelectrodes using chromophore assembly‐functionalized covalent networks for boosting eight‐electron reduction of nitrate to ammonia. Upon sunlight irradiation, the photoelectrode stores a mass of reducing equivalents at the photoexcited chromophore assembly for multielectron reduction of a copper catalyst, enabling efficient nitrate reduction to ammonia. By introducing the new photoelectrode structure, it is demonstrated that the electronic interplay between charge photo‐accumulating assembly and multi‐electron redox catalysts can be optimized to achieve proper balance between electron transfer dynamics and thermodynamic output of photoelectrocatalytic systems. [ABSTRACT FROM AUTHOR]

3D porous organic frameworks, which possess the advantages of high surface area and abundant exposed active sites, are considered ideal platforms to accommodate single atoms (SAs) and metal nanoclusters (NCs) in high‐performance catalysts; however, very little research has been conducted in this field. In the present work, a 3D porous organic framework containing Ni1 SAs and Nin NCs is prepared through the metal‐assisted one‐pot polycondensation of tetraaldehyde and hexaaminotriptycene. The single metal sites and metal clusters confined in the 3D space created a favorable micro‐environment that facilitated the activation of chemically inert CO2 molecules, thus promoting the overall photoconversion efficiency and selectivity of CO2 reduction. The 3D‐NiSAs/NiNCs‐POPs, as a CO2 photoreduction catalyst, demonstrated an exceptional CO production rate of 6.24 mmol g−1 h−1, high selectivity of 98%, and excellent stability. The theoretical calculations uncovered that asymmetrical interaction between Ni1 SAs and Nin NCs not only favored the bending of CO2 molecules and reducing the CO2 reduction energy, but also regulated the electronic structure of the catalyst leading to the optimal binding strength of intermediates. [ABSTRACT FROM AUTHOR]

Adapting the coordination environment to influence the electronic configuration of active sites represents an efficient approach for improving the photocatalytic performance of the CO2 reduction reaction (CO2RR) but how to execute it precisely remains challenging. Herein, heteroatom‐substitution in Ni‐porphyrin to break the coordination symmetry of Ni center is proposed to be an effective solution. Based on this, two symmetry‐breaking Ni‐porphyrins, namely Ni(Cl)ON3Por and Ni(Cl)SN3Por, are designed and successfully prepared. By theoretical calculation, it is found that symmetry‐breaking efficiently regulates the 3d orbital energy levels of Ni center. Furthermore, experimental and theoretical findings jointly revealed that coordination symmetry‐breaking of Ni‐porphyrins facilitates the generation of highly reactive NiI species during the catalytic process, effectively stabilizing and reducing the energy barrier of formation of the key *COOH intermediate. As a result, Ni(Cl)ON3Por and Ni(Cl)SN3Por gave CO production rates of 24.7 and 38.8 mmol g−1 h−1 as well as selectivity toward CO of 94.0% and 96.4%, respectively, outperforming that of symmetric NiN4Por (CO production rate of 6.6 mmol g−1 h−1 and selectivity of 82.8%). These findings offer microscopic insights into how to modulate the catalytic activity by precisely tuning the coordination environment of active sites and rational design of competent catalyst for CO2RR photocatalysis. [ABSTRACT FROM AUTHOR]

Photocatalytic nitrogen reduction represents a viable technology for green ammonia synthesis under mild conditions. However, the performance of the photocatalysts is typically limited by high charge carrier recombination and low adsorption and activation of nitrogen molecules. Herein, Bi/Bi2Sn2O7 (Bi/BSO) heterojunction nanocomposites are prepared via a one‐step hydrothermal method, where NaOH etching of oxygen vacancies in the Bi─O bonds of Bi2Sn2O7 (BSO) is exploited for the in situ formation of metallic Bi and hence Schottky junctions with the semiconducting BSO. This leads to a high separation rate of photogenerated charge carriers. Consequently, compared to the pure‐phase BSO, the Bi/BSO heterostructures exhibit markedly enhanced ammonia production, reaching an optimum rate of 284.5 µmol g−1 h−1, where the rectifying contact between the semiconducting BSO and metallic Bi facilitates directional BSO to Bi electron transfer, leading to enrichment of photogenerated electrons at the active sites of metallic Bi. First‐principles calculations confirm the alteration of active sites and the guided electron flow by the Schottky junctions and surface oxygen vacancies. Results from this study offer an effective paradigm of structural engineering in manipulating the photocatalytic activity of bismuth‐based pyrochlore materials toward nitrogen fixation to ammonia. [ABSTRACT FROM AUTHOR]

The dual photothermal effects resulting from the non-radiative photon conversion of the D-A structure and the Au NPs LSPR effect, along with the enhanced charge carrier dynamics, catalyzed the efficient photoreduction of CO 2. [Display omitted] Conversion of CO 2 into high value-added fuels through the photothermal effect is an effective approach for utilizing solar energy. In this study, we prepared the CN-based photocatalyst Py-CTN-Au with both donor-acceptor (D-A) system and dual photothermal effects using a simple two-step method involving calcination and photo-deposition. Real-time monitoring with a thermal imaging camera revealed that Py-CTN-Au0.5 achieved a maximum stable temperature of 180 °C, which was approximately 1.2 times higher than that of Py-CTN (155 °C) and 1.9 times higher than that of g-CN (95 °C) under the same reaction conditions. Under the optimized reaction conditions, Py-CTN-Au0.5 exhibited a CO release rate of 30.59 umol g−1 after 4 h of reaction, which was 7.3 times higher than that of pure g-CN (4.18 umol g−1). The D-A system not only facilitated the separation and transformation of charge carriers but also induced a photothermal effect to accelerate the photoreduction of CO 2. Additionally, the cocatalyst Au nanoparticles (Au NPs) further enhanced the charge carrier dynamics and photothermal effect by increasing the built-in electric field intensity and localized surface plasmon resonance (LSPR) effect, respectively. The dual photothermal effects resulting from the non-radiative photon conversion of the D-A structure and the Au NPs LSPR effect, along with the enhanced charge carrier dynamics, catalyzed the efficient photoreduction of CO 2. DFT simulations were used to confirm the effect of D-A system and Au NPs. In-situ FTIR results demonstrated that the synergistic photothermal effect promoted the formation of the key intermediate species COOH*, which is beneficial for the photocatalytic reduction of CO 2. This study provides valuable insights into the multiple photothermal synergistic effects in photocatalytic reactions. [ABSTRACT FROM AUTHOR]

[Display omitted] The efficiency of CO 2 photocatalytic reduction is severely limited by inefficient separation and sluggish transfer. In this study, spin polarization was induced and built-in electric field was strengthened via Co doping in the BiVO 4 cell to boost photocatalytic CO 2 reduction. Results showed that owing to the generation of spin-polarized electrons upon Co doping, carrier separation and photocurrent production of the Co-doped BiVO 4 were enhanced. CO production during CO 2 photocatalytic reduction from the Co-BiVO 4 was 61.6 times of the BiVO 4. Notably, application of an external magnetic field (100 mT) further boosted photocatalytic CO 2 reduction from the Co-BiVO 4 , with 68.25 folds improvement of CO production compared to pristine BiVO 4. The existence of a built-in electric field (IEF) was demonstrated through density functional theory (DFT) simulations and kelvin probe force microscopy (KPFM). Mechanism insights could be elucidated as follows: doping of magnetic Co into the BiVO 4 resulted in increased the number of spin-polarized photo-excited carriers, and application of a magnetic field led to an augmentation of intrinsic electric field due to a dipole shift, thereby extending carrier lifetime and suppressing charges recombination. Additionally, HCOO− was a crucial intermediate in the process of CO 2 RR, and possible pathways for CO 2 reduction were proposed. This study highlights the significance of built-in electric fields and the important role of spin polarization for promotion of photocatalytic CO 2 reduction. [ABSTRACT FROM AUTHOR]

[Display omitted] • Interfacial complexation of Fe3+ and Bi 2 MoO 6 is established in the presence of PDS. • The complexation between Fe3+ and Bi 2 MoO 6 accelerates the Fe3+/Fe2+ cycle. • Efficient organic contaminants degradation is achieved by Bi 2 MoO 6 /Fe3+/PDS/Vis system. • The Fe3+/Fe2+ redox cycle is employed to promote the continuous activation of PDS. To address the observed decrease in efficiency during Fe2+-mediated persulfate (PDS) activation caused by slow electron transfer rates and challenges in cycling between Fe3+/Fe2+ states, we devised a strategy to establish interfacial complexation between Fe3+ and Bi 2 MoO 6 in the presence of PDS. The proposed approach facilitates more efficient capture of photogenerated electrons, thereby accelerating the rate-limiting reduction process of the Fe3+/Fe2+ cycle under visible light irradiation and promoting PDS activation. The Bi 2 MoO 6 /Fe3+/PDS/Vis system demonstrates complete degradation of organic pollutants, including Atrazine (ATZ), carbamazepine (CBZ), bisphenol A (BPA), and 2,4-dichlorophenol (DCP) at a concentration of 10 mg/L within a rapid reaction time of 30 min. Radical scavenging experiments and electron paramagnetic resonance spectra (EPR) confirm that the sulfate radical (•SO 4 −) is the dominant species responsible for organic contaminant degradation. The real-time conversion process between Fe3+ and Fe2+ was monitored by observing changes in iron species forms and concentrations within the reaction system. X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy verify the formation of a complexation between Fe3+ and Bi 2 MoO 6 , facilitating anchoring of Fe3+ onto material surface. Based on these findings, we propose a reliable mechanism for the activation reaction. This work presents a promising heterogeneous PDS activation method based on Fe3+/Fe2+ cycle for water treatment. [ABSTRACT FROM AUTHOR]

Thin films of CuO wrapped around a skeleton were synthesised using nickel foam (NF) as a carrier and g-C 3 N 4 was embedded in it to generate NF@Cu/g-C 3 N 4 monolithic catalysts. The slow kinetics of photocatalytic reduction of CO 2 and the low quantum efficiency achieved, which is directly related to the photocatalyst and reactor configurations, limit the wide application of this technology. In light of this, a novel pod-like NF@Cu/g-C 3 N 4 monolithic photomicroreactor system was developed in this study to improve the efficiency of visible light-responsive CO 2 reduction to methanol. Micro-morphology and pore volume characterization showed that the incorporation of CuO and g-C 3 N 4 significantly increased the specific surface area and pore volume of Ni foam. The novel monolithic photomicro reactor was evaluated using methanol yield as an indicator, and the experimental results showed that the performance of the mesoporous NF@Cu/g-C 3 N 4 photomicroreactor was significantly better than that of the NF@CuO photomicroreactor as well as the tubular reactor. The average CH 3 OH yields were 6.47 and 9.85 times higher than those of pure CuO and pure g-C 3 N 4. The results showed that the methanol concentration and yield tended to increase and then decrease with the increase in liquid flow rate. The experimental results fully demonstrate the superiority of the newly developed NF@Cu/g-C 3 N 4 monolithic photomicroreaction system in enhancing the CO 2 photoreduction performance. [ABSTRACT FROM AUTHOR]

Photoinduced single‐electron reduction is an efficient method for the mono‐selective activation of the C−F bond on a trifluoromethyl group to construct a difluoroalkyl group. We have developed an electron‐donor‐acceptor (EDA) complex mediated single‐electron transfer (EDA‐SET) of α,α,α‐trifluoromethyl arenes in the presence of lithium salt to give α,α‐difluoroalkylarenes. The C−F bond reduction was realized by lithium iodide and triethylamine, two common feedstock reagents. Mechanistic studies revealed the generation of a α,α‐difluoromethyl radical by single‐electron reduction and defluorination, followed by the radical addition to alkenes. Lithium salt interacted with the fluorine atom to promote the photoinduced reduction mediated by the EDA complex. Computational studies indicated that the lithium‐assisted defluorination and the single‐electron reduction occurred concertedly. We call this phenomenon fluoride‐coupled electron transfer (FCET). FCET is a novel approach to C−F bond activation for the synthesis of organofluorine compounds. [ABSTRACT FROM AUTHOR]

One of the important research components of photocatalytic research is the development of new photocatalysts, and recent studies have shown the rise of borate‐type photocatalysts. This paper focuses on the photoreduction of potassium dichromate and the photodegradation of rhodamine B by two borate composites under simulated sunlight. A coral‐like borate was obtained by sol‐gel preparation and then assembled by photodeposition with Pt nanoparticles dots or CuO particles to obtain the new composites with excellent performance. The kinetic constants of photocatalytic properties of 2 %Pt/Gd0.85Ce0.15B5O9 and 2.5 %CuO/Gd0.90Ce0.10B5O9 samples in the reduction and degradation reactions are 0.0050 min−1 and 0.0150 min−1, which are 25 and 4.2 times of the intrinsic GdB5O9 sample respectively. The results of the study indicate the research promise of developing new visible photocatalysts based on borates, especially for photocatalytic applications for pollutant removal. [ABSTRACT FROM AUTHOR]

This study explores photocatalytic conversion of CO2 using TiO2−Cu heterojunctions with different Cu contents and investigates influence of different reaction media on the process efficiency. The use of KOH favored liquid products, especially ethanol. An analysis of H2 production as the main competitive reaction was done. Sodium oxalate led to an increase in H2 evolution by approximately 600 μmol g‐1 compared to pure water, in the presence of CO2 in the reaction medium, but the blank test (without CO2) indicates a lower H2 yield (~136 μmol g−1), which suggests that the competitive reaction with CO2 also plays a role in H2 production. This role was related to the decrease of the initial pH from approximately 8.5 to 5.2, stabilizing at 5.5 at the end of the 6 h reaction. In an environment saturated with N2, the pH increases to 9 and stabilizes at 7.8 at the end of the process. In the presence of acetic acid, both CO and H2 production were suppressed, with a significant increase in the selectivity for methane via cleavage of the acid's carbon bond. The findings underscore the importance of optimizing reaction conditions to achieve higher yields of desired products in the photocatalytic conversion of CO2. [ABSTRACT FROM AUTHOR]

Photocatalytic oxygen reduction reactions and water oxidation reactions are extremely promising green approaches for massive H2O2 production. Nonetheless, constructing effective photocatalysts for H2O2 generation is critical and still challenging. Since the network topology has significant impacts on the electronic properties of two dimensional (2D) polymers, herein, for the first time, we regulated the H2O2 photosynthetic activity of 2D covalent organic frameworks (COFs) by topology. Through designing the linking sites of the monomers, we synthesized a pair of novel COFs with similar chemical components on the backbones but distinct topologies. Without sacrificial agents, TBD‐COF with cpt topology exhibited superior H2O2 photoproduction performance (6085 and 5448 μmol g−1 h−1 in O2 and air) than TBC‐COF with hcb topology through the O2‐O2⋅−‐H2O2, O2‐O2⋅−‐O21‐H2O2, and H2O‐H2O2 three paths. Further experimental and theoretical investigations confirmed that during the H2O2 photosynthetic process, the charge carrier separation efficiency, O2⋅− generation and conversion, and the energy barrier of the rate determination steps in the three channels, related to the formation of *OOH, *O21, and *OH, can be well tuned by the topology of COFs. The current study enlightens the fabrication of high‐performance photocatalysts for H2O2 production by topological structure modulation. [ABSTRACT FROM AUTHOR]

We report a family of donor‐acceptor thermally activated delayed fluorescent (TADF) compounds based on derivatives of DMAC‐TRZ, that are strongly photoreducing. Both Eox and thus E*ox could be tuned via substitution of the DMAC donor with a Hammett series of p‐substituted phenyl moieties while Ered remained effectively constant. These compounds were assessed in the photoinduced dehalogenation of aryl halides, and analogues bearing electron withdrawing groups were found to produce the highest yields. Substrates of up to Ered=−2.72 V could be dehalogenated at low PC loading (1 mol %) and under air, conditions much milder than previously reported for this reaction. Spectroscopic and chemical studies demonstrate that all PCs, including literature reference PCs, photodegrade, and that it is these photodegradation products that are responsible for the reactivity. [ABSTRACT FROM AUTHOR]

Photocatalytic oxygen reduction reactions and water oxidation reactions are extremely promising green approaches for massive H2O2 production. Nonetheless, constructing effective photocatalysts for H2O2 generation is critical and still challenging. Since the network topology has significant impacts on the electronic properties of two dimensional (2D) polymers, herein, for the first time, we regulated the H2O2 photosynthetic activity of 2D covalent organic frameworks (COFs) by topology. Through designing the linking sites of the monomers, we synthesized a pair of novel COFs with similar chemical components on the backbones but distinct topologies. Without sacrificial agents, TBD‐COF with cpt topology exhibited superior H2O2 photoproduction performance (6085 and 5448 μmol g−1 h−1 in O2 and air) than TBC‐COF with hcb topology through the O2‐O2⋅−‐H2O2, O2‐O2⋅−‐O21‐H2O2, and H2O‐H2O2 three paths. Further experimental and theoretical investigations confirmed that during the H2O2 photosynthetic process, the charge carrier separation efficiency, O2⋅− generation and conversion, and the energy barrier of the rate determination steps in the three channels, related to the formation of *OOH, *O21, and *OH, can be well tuned by the topology of COFs. The current study enlightens the fabrication of high‐performance photocatalysts for H2O2 production by topological structure modulation. [ABSTRACT FROM AUTHOR]

We report a family of donor‐acceptor thermally activated delayed fluorescent (TADF) compounds based on derivatives of DMAC‐TRZ, that are strongly photoreducing. Both Eox and thus E*ox could be tuned via substitution of the DMAC donor with a Hammett series of p‐substituted phenyl moieties while Ered remained effectively constant. These compounds were assessed in the photoinduced dehalogenation of aryl halides, and analogues bearing electron withdrawing groups were found to produce the highest yields. Substrates of up to Ered=−2.72 V could be dehalogenated at low PC loading (1 mol %) and under air, conditions much milder than previously reported for this reaction. Spectroscopic and chemical studies demonstrate that all PCs, including literature reference PCs, photodegrade, and that it is these photodegradation products that are responsible for the reactivity. [ABSTRACT FROM AUTHOR]

The advancement of semiconductor photocatalysis is acknowledged for its prowess as an eco-friendly, energy-efficient, and cost-effective method facilitating diverse organic transformations, including CO 2 photoreduction. Despite its merits, there remains room for enhancing the selectivity and efficiency of these photocatalysts. In this study, we successfully synthesized heterojunction nanocomposites comprising CdS and Bi 2 WO 6 semiconductors to drive the CO 2 -to-methanol conversion, achieving a maximum yield of 9450 μmol/g. Notably, CO (1048 μmol/g) and H 2 (482 μmol/g) were also produced using water within a 16-h photocatalytic period, yielding an average production rate of ∼590 μmol/g-h. Triethylamine played a crucial role by providing electrons to the reaction system. The recovered photocatalyst exhibited consistent performance over five cycles of photoreduction experiments. Various spectroscopic and microscopic techniques were employed to analyze the optical, catalytic, and morphological properties of both the fresh and recovered photocatalysts. The introduced S-scheme heterojunction photocatalyst stands out for its efficient charge carrier separation, enhancing redox capacity, and holds promise as a source for novel strategies to improve the efficiency of CO 2 photoreduction experiments. [Display omitted] [ABSTRACT FROM AUTHOR]

The internal electron transport capacity of the semiconductor directly affects whether there is a sufficient number of photogenerated electrons involved in the catalytic reaction process, thus determining the photocatalytic efficiency. Indium tin oxide (ITO), as an excellent conductive material, has convenient internal electron transport and can be used as a good photocatalyst directly. In this paper, ITO films on three different conductive substrates were prepared by DC sputtering method, and the crystallization and appearance of each sample were compared. Different substrates affect the energy band position of catalyst. The performance of photocatalytic CO 2 reduction was tested. We found that ITO films grown on carbon cloth (CC) substrate have good photocatalytic properties. The atmosphere ratio in the preparation process also has a certain influence on the performance of the sample. Compared with ITO conductive glass widely used in the market, our improved ITO film has better photocatalytic properties and practicability. This work provides a certain reference for the application of ITO in the field of photocatalysis. [ABSTRACT FROM AUTHOR]

Photocatalysis CO 2 conversion to valuable hydrocarbons driven by solar energy holds great potential in alleviating the greenhouse effect and energy shortage. However, the photocatalytic CO 2 reduction activity is hindered by the high charge recombination rate and low CO 2 affinity of semiconductor photocatalyst. Herein, a series of fluorine lattice-doped ZnS catalysts with accompanying sulfur vacancies (V S) are prepared via a facile hydrothermal method. Fluorine doped ZnS catalysts exhibit remarkedly enhanced photocatalytic performance for selective CO 2 reduction to CO compared to the bulk counterpart, and it is the ZnS 0.95 F 0.05 achieves the highest photoactivity among the as-obtained catalysts. Without cocatalysts or sacrificial reagents, ZnS 0.95 F 0.05 enables CO 2 photoreduction to CO with an outstanding yield of 16.04 μmol g−1 h−1 and high selectivity of 84%, about 6 times higher than that of ZnS (2.68 μmol g−1 h−1), surpassing most of the previously reported photocatalysts. The improved activity for fluorine doped ZnS can be due to the promoted carrier separation and CO 2 adsorption, owing to the synergistic effect of fluorine doping and concomitant Vs, based on the experimental verification and theoretical calculation. This study offers an effective approach to design photocatalysts for high performance CO 2 reduction. [ABSTRACT FROM AUTHOR]

Regio‐ and chemo‐selective functionalization of electron deficient azaarenes often required their transformations to corresponding N‐oxides and subsequent removal of oxygen after functionalization to get back the desired substituted azaarenes. An efficient metal‐free visible‐light photo‐redox catalytic deoxygenation of N‐oxides of azaheterocyclic compounds has been developed using acridinium based organo‐photocatalyst in blue LED light. High efficiency and mildness of this methodology has been demonstrated through higher deoxygenation yield of wide variety of azaheterocyclic N‐oxides with reactive functional groups. Robustness of the photocatalytic reduction has been demonstrated through easy scaling‐up of the reaction to gram level without much change in the reaction yield. [ABSTRACT FROM AUTHOR]

In the face of the growing energy crisis and environmental challenges, substantial efforts are now directed toward sustainable clean energy as a replacement for traditional fossil fuels. CO2 photoreduction into value‐added chemicals and fuels is widely recognized as a promising approach to mitigate current energy and environmental concerns. Photocatalysts comprising single atoms (SAs) supported on two‐dimensional (2D) semiconducting materials (SAs‐2DSemi) have emerged as a novel frontier due to the combined merits of SA catalysts and 2D materials. In this study, we review advancements in metal SAs confined on 2DSemi substrates, categorized into four groups: (1) metal oxide‐based, (2) g‐C3N4‐based, (3) emerging, and (4) hybridized 2DSemi, for photocatalytic CO2 conversion over the past few years. With a particular focus on highlighting the distinct advantages of SAs‐2DSemi, we delve into the synthesis of state‐of‐the‐art catalysts, their catalytic performances, and mechanistic elucidation facilitated by experimental characterizations and theoretical calculations. Following this, we outline the challenges in this field and offer perspectives on harnessing the potential of SAs‐2DSemi as promising photocatalysts. This comprehensive review aims to provide valuable insights for the future development of 2D photocatalytic materials involving SAs for CO2 reduction. [ABSTRACT FROM AUTHOR]

Solid solutions are garnering substantial attention in the realm of solar energy utilization due to their tunable electronic properties, encompassing band edge positions and charge‐carrier mobilities. In this study, we designed and synthesized Co1‐xZnxFe2xGa2–2xO4 (0

Single‐atom photocatalysts (SAPs) engineered on various supports offer a promising pathway to efficiently convert CO2 into high‐valued products. However, most SAPs with near‐planar metal atom coordination structure suffer from low conversion efficiency, mainly due to the weak local polarized electric field which retards the reaction kinetics. Herein, this study reports for the first time a photocatalyst which simultaneously integrates protruding‐shaped Co single atom and strong polarization field in ultrathin crystalline covalent‐triazine‐framework nanosheets (donate as Co1/CTF‐NSs). Both experimental results and theoretical simulations demonstrated that giant local polarization field is successfully triggered on the Co1/CTF‐NSs, which induced directional charge migration and greatly promoted the separation of photogenerated carriers. The protruding‐Co centers enhanced the overlap between CO2 2p and Co 3d orbitals, thereby facilitating a strong affinity for CO2 adsorption. Furthermore, the local polarization fields between the protruding‐Co and CO2 drove the injection of a substantial number of electrons from Co 3d into CO2 π antibonding orbitals, leading to the effective activation and reduction of the CO2 molecules. Consequently, the as‐synthesized Co1/CTF‐NSs exhibited a remarkable CO production rate of 5391 µmol g−1 h−1 and a high selectivity (97.3%) under visible light irradiation, which represents one of the best molecular framework photocatalysts to date. [ABSTRACT FROM AUTHOR]

The elevated level of carbon dioxide (CO2) in the troposphere is playing a crucial role in changing the earth's climatic system. Excess CO2 concentration is trapping a substantial proportion of heat imparting adverse range of environmental effects like extreme weather events, agricultural impacts and disruption of the ecosystem. Strategies such as CO2 capturing and storage are being pursued using polyoxometalates (POMs) to mitigate the elevated level of CO2 and their efficient conversion into useful chemicals. This review outlines the importance of CO2 reduction by electrocatalytic and photocatalytic reduction of CO2. POMs have several advantages for CO2 activation because of their promising catalytic activity, high selectivity and versatility for incorporating different metal ions and ligands. The efficient redox active metal center facilitates the conversion of CO2 by providing sufficient activation energy. Their robust structure also enables them resist harsh conditions, including high temperature and acidic or basic conditions. Owing to these properties, POMs can be a catalyst, co‐catalyst, photosensitizer or multielectron donor for CO2 reduction. Finally, we stated the challenges and future insight for CO2 activation using POMs. [ABSTRACT FROM AUTHOR]

The support of powdered catalysts on mold bodies facilitates their handling and reusability. In case of photocatalytic applications, such as enhanced water purification processes, transparent supports with thin layers of the active material are desirable to obtain an optimal light efficiency. For the generation of such layers a precise control of layer thickness is crucial. Here, a multi‐step dip‐coating approach for the generation of TiO2 layers with varying thickness on glass rings is reported. Additionally, the coated glass rings were tested in the photocatalytic reduction of nitrate in aqueous solution under simulated sunlight. [ABSTRACT FROM AUTHOR]

[Display omitted] Regulating product selectivity in photocatalytic CO 2 reduction to enhance the yield of valuable hydrocarbons remains a formidable challenge because of the diversity of reduction products and the competitive reduction of H 2 O. Herein, ultrathin Bi 2 O 3 / Co–doped SrBi 4 Ti 4 O 15 S–scheme photocatalysts (Co–BS) were synthesized using a hydrothermal method. The Bi 2 O 3 /Co–doped SrBi 4 Ti 4 O 15 photocatalyst exhibited significantly higher selectivity for CH 4 (62.3 μmolg−1) and CH 3 OH (54.1 μmolg−1) in CO 2 reduction compared with pure SrBi 4 Ti 4 O 15 (27.2 and 0.8 μmolg−1) and the Bi 2 O 3 /SrBi 4 Ti 4 O 15 S–scheme without Co (30.2 and 0 μmolg−1). The experimental results demonstrated that the inclusion of Co into SrBi 4 Ti 4 O 15 expanded the range of light absorption and generated an internal electric field between Co–doped SrBi 4 Ti 4 O 15 and Bi 2 O 3. Density functional theory calculations and other experimental findings confirmed the formation of a new doping energy level in the Bi 2 O 3 /SrBi 4 Ti 4 O 15 S–scheme heterojunction after Co doping. The valence band electrons of Bi 2 O 3 /SrBi 4 Ti 4 O 15 transitioned to the Co–doped level because of the interconversion between Co3+ and Co2+ under the action of the internal electric field. Furthermore, the corresponding characterizations revealed that the adsorption and electron transfer rates of the surface active sites were accelerated after Co doping, enhancing electron involvement in the photocatalytic reaction process. This study presented a metal–doped S–scheme heterojunction approach for CO 2 reduction to produce high–value products, enhancing the conversion of solar energy into energy resources. [ABSTRACT FROM AUTHOR]

[Display omitted] • Oxygen vacancy and isolated Ti3+ embed into interface of a Z-scheme heterojunction. • Calcination precisely regulated oxygen vacancy and isolated Ti3+ in the interface. • The interface showed superior photocatalytic CO 2 reduction activity to reported ones. • The interfacial modification greatly promoted CO 2 activation and reduction activity. Exploring the real force that drives the separation of Coulomb-bound electron-hole pairs in the interface of heterojunction photocatalysts can establish a clear mechanism for efficient solar energy conversion efficiency. Herein, the formation of oxygen vacancy (Ov) and isolated Ti3+ was precisely regulated at the interface of g-C 3 N 4 /TiO 2 Z-scheme heterojunction (g-C 3 N 4 /Ov-Ti3+-TiO 2) by optimizing the opening degree of the calcination system, showing excellent production rate of CO and CH 4 from CO 2 photoreduction under visible light. This photocatalytic system also exhibited prominent stability. Combining theoretical calculation and characterization, the introduction of Ov and isolated Ti3+ on the interface could construct a charge transfer channel to break the forbidden transition of n → π*, improving the separation process of photoexcited electron-hole pairs. The photoexcited electrons weakened the covalent interaction of C O bonds to promote the activation of adsorbed inert CO 2 molecules, significantly reducing the energy barrier of the rate-limiting step during CO 2 reduction. This work demonstrates the great application potential of reasonably regulating heterojunction interface for efficient photocatalytic CO 2 reduction. [ABSTRACT FROM AUTHOR]

Anthraquinone-induced asymmetric N 3 −Sb−O coordination was constructed on C 3 N 4 matrix by a rapid and simple explosive crystallization approach, which contributes to selective O 2 photoreduction to H 2 O 2. [Display omitted] Achieving O 2 photoreduction to H 2 O 2 with high selectivity control and durability while using easily accessible catalyst requires new synthesis strategies. Herein, we propose an asymmteric Sb coordination active center strategy of introducing anthraquinone (AQ) and heptazine to form local N 3 − Sb − O coordination by a rapid and simple explosive crystallization approach, resulting in a mesoporous conjugated heptazine-amide-AQ polymer coordinated Sb (HAAQ-Sb). It is demonstrated that the N 3 − Sb − O coordination effectively suppresses the charge recombination and acts as the highly active site for O 2 adsorption. Moreover, as-introduced AQ units initiate low-barrier hydrogen transfer through a reversible redox process that triggers highly-efficient H 2 O 2 production. A superior apparent quantum yield of 20.2 % at 400 nm and a remarkable solar-to-chemical conversion efficiency of 0.71 % are achieved on the optimal HAAQ-Sb, which is the highest among C 3 N 4 -based photocatalysts at present. This asymmetric coordination concept and material design method provide new perspectives for the research of novel catalysts toward artificial photosynthesis. [ABSTRACT FROM AUTHOR]

[Display omitted] The creation of a Z-scheme heterojunction is a sophisticated strategy to enhance photocatalytic efficiency. In our study, we synthesized an In 2 S 3 /MnO 2 /BiOCl dual Z-scheme heterostructure by growing BiOCl nanoplates on the sheets of In 2 S 3 nanoflowers, situated on the surface of MnO 2 nanowires. This synthesis involved a combination of hydrothermal and solution combustion methods. Experiments and density functional theory (DFT) calculations demonstrated that the In 2 S 3 /MnO 2 /BiOCl composite exhibited notable photo reduction performance and photocatalytic stability. This was attributed to the pivotal roles of BiOCl and MnO 2 in the composite, acting as auxiliaries to enhance the electronic structure and facilitate the adsorption/activation capacity of CO 2 and H 2 O. The yield rates of CO, CH 4 , and C 2 H 4 over In 2 S 3 /MnO 2 /BiOCl as the catalyst were 3.94, 5.5, and 3.64 times higher than those of pure In 2 S 3 , respectively. Photoelectrochemical analysis revealed that the dual Z-scheme heterostructure, with its oxygen vacancies and large surface area, enhanced CO 2 absorption and active sites on the nanoflower/nanowire intersurfaces. Consequently, the dual Z-scheme charge transfer pathway provided efficient channels for boosting electron transfer and charge separation, resulting in high C 2 H 4 , CH 4 , and CO yields of formed and exihibits an promising photoreduction rate of CO 2 to CO (51.2 µmol/g.h), CH 4 (42.4 µmol/g.h) and C 2 H 4 (63.2 µmol/g.h), respectively. DFT, in situ Diffuse reflectance infrared fourier transform spectroscopy, and temperature-programmed desorption tests were employed to verify the intermediates pathway. The study proposed a potential photocatalytic mechanism based on these findings. [ABSTRACT FROM AUTHOR]

[Display omitted] Graphitic carbon nitride (g-C 3 N 4 , CN) has garnered considerable attention in the field of photocatalysis due to its favorable band gap and high specific surface area. However, its primary practical limitation lies in the strong radiative recombination of lone pair (LP) electronic states, leading to limited efficiency in separating photogenerated carriers and subsequently diminishing photocatalytic performance. In this study, we devised and synthesized a heterojunction photocatalytic system comprising TiO 2 nanosheets supported on modified g-C 3 N 4 (MCN), designated as MCN/TiO 2. The presence of C N functional groups on the tri-s-triazine nitrogen captures photogenerated electrons by modifying LP electronic states, resulting in a reduction in the fluorescence emission intensity of g-C 3 N 4. Simultaneously, it forms chemical bonds with the supported TiO 2 nanosheets, creating an efficient electron transfer pathway for the accumulation of photogenerated electrons at the active Ti sites. Experimentally, the MCN/TiO 2 photocatalytic system exhibited optimal performance in CO 2 reduction. The CH 4 production rate reached 26.59 μmol g−1 h−1, surpassing that of TiO 2 and CN/TiO 2 by approximately 8 and 3 times, respectively. Furthermore, this photocatalytic system demonstrated exceptional photostability over five cycles, each lasting 4 h. This research offers a valuable approach for the efficient separation and transfer of photogenerated carriers in composite materials based on g-C 3 N 4. [ABSTRACT FROM AUTHOR]

Van der Waals (vdW) heterojunctions enhance photocatalyst efficiency but face electron transfer challenges at component interfaces due to large spacing and potential barriers. We introduce a novel wet chemistry approach to enhance the efficiency of photocatalysts by creating a functionalized graphene-modulated Z-scheme vdW heterojunction (xZnPc/yG-WO 3) to eliminate interfacial potential differences, enabling better electron transfer for improved photocatalytic reactions and molecular dispersion. [Display omitted] The construction of van der Waals (vdW) heterojunctions is a key approach for efficient and stable photocatalysts, attracting marvellous attention due to their capacity to enhance interfacial charge separation/transfer and offer reactive sites. However, when a vdW heterojunction is made through an ex-situ assembly, electron transmission faces notable obstacles at the components interface due to the substantial spacing and potential barrier. Herein, we present a novel strategy to address this challenge via wet chemistry by synthesizing a functionalized graphene-modulated Z-scheme vdW heterojunction of zinc phthalocyanine/tungsten trioxide (xZnPc/yG-WO 3). The functionalized G-modulation forms an electron "bridge" across the ZnPc/WO 3 interface to improve electron transfer, get rid of barriers, and ultimately facilitating the optimal transfer of excited photoelectrons from WO 3 to ZnPc. The Zn2+ in ZnPc picks up these excited photoelectrons, turning CO 2 into CO/CH 4 (42/22 μmol.g−1.h−1) to deliver 17-times better efficiency than pure WO 3. Therefore, the introduction of a molecular "bridge" as a means to establish an electron transfer conduit represents an innovative approach to fabricate efficient photocatalysts designed for the conversion of CO 2 into valued yields. [ABSTRACT FROM AUTHOR]

[Display omitted] • 2D In 2 O 3 is decorated on 2D BiOBr to form a Z-scheme heterojunction. • This work achieves improved internal electric field and charge separation. • The B 3 I 1 composite exhibits enhanced photocatalytic activity. • The mechanism of photocatalytic CO 2 reduction into CO is proposed. CO 2 photocatalytic reduction is an excellent strategy for promoting solar-to-chemical energy conversion and alleviating the severe environmental crisis. In this study, 2D indium oxide (IO) is decorated on 2D bismuth oxybromide (BOB) nanosheets to gain BOB/IO (B x I y) heterojunction. The optimal B 3 I 1 composite affords a CO production rate of 54.2 μmol⋅g−1, about 2.2 times and 11.3 times higher than those of the pristine BOB and IO, respectively. The introduction of IO significantly enhances the internal electric field (IEF), leading to accelerated charge transfer and prolonged lifetime of the photogenerated carriers. In the B x I y composite, the BOB and IO serve as the electron acceptor and donor, respectively, facilitating the reduction of CO 2 and oxidation of H 2 O. In-situ DRIFTs spectra are used to confirm the catalytic active sites and provide insights into the mechanism of CO 2 photoreduction. The results suggest *COOH and *CO 2 – species played a crucial role in the formation of CO. This work presents a valuable perspective on understanding the charge transfer route and developing highly efficient photocatalysts for CO 2 photoreduction. [ABSTRACT FROM AUTHOR]

Photocatalytic conversion of renewable biomass‐derived aldehydes into high‐valued chemicals is a promising path to meet the growing demand for clean energy and chemical resources. However, the approach still faces challenges, such as limited reaction types and low utilization rates due to the complex functional groups and involved polytropic reaction. In the present work, we developed a catalyst of Pt nanoparticles (Pt NPs) supported on a NiO–In2O3 bimetallic oxide (denoted as Pt/NiInOx) for photocatalytic hydrogenation of furfural (FAL) to furfural alcohol (FOL). Owing to the excellent band structure and efficient internal charge transfer on the p–n heterojunction in the catalyst, the highest 99.9% yield to FOL was obtained over the Pt/NiInOx under a light‐emitting diode (LED) light at low temperatures as 273 K. The combination of ·H dissociated from H2 and oxygen vacancy work synergically to adsorb, activate, and converse C=O to the C–O group. The photocatalytic system presents a highly efficient approach for the rapid hydrogenation of biomass‐based aldehydes under a low LED light radiation intensity at a low temperature. The work is expected to serve as an important reference in constructing bimetallic oxide‐supported active metals, enabling efficient separation of photogenerated electrons and holes, and offering oxygen vacancies in various photocatalytic reactions. [ABSTRACT FROM AUTHOR]

Homogenous molecular photocatalysts for CO 2 reduction, especially metal complex-based photosensitizer‒catalyst assemblages, have been attracting extensive research interests due to their efficiency and customizability. However, their low durability and recyclability limit practical applications. In this work, we immobilized the catalysts of metal terpyridyl complexes and the photosensitizer of [Ru(bpy) 3 ]Cl 2 onto the surface of carbon nanotubes through covalent bonds and electrostatic interactions, respectively, transforming the homogeneous system into a heterogeneous one. Our characterizations prove that these metal complexes are well dispersed on CNTs with a high loading (ca. 12 wt.%). Photocatalytic measurements reveal that catalytic activity is remarkably enhanced when the molecular catalysts are anchored, which is three times higher than that of homogeneous molecular catalysts. Moreover, when the photosensitizer of [Ru(bpy) 3 ]Cl 2 is immobilized, the side reaction of hydrogen evolution is completely suppressed and the selectivity for CO production reaches 100%, with its durability also significantly improved. This work provides an effective pathway for constructing heterogeneous photocatalysts based on rational assembly of efficient molecular photosensitizers and catalysts. [ABSTRACT FROM AUTHOR]

Highly crystalline carbon nitride polymers have shown great opportunities in overall water photosplitting; however, their mission in light-driven CO 2 conversion remains to be explored. In this work, crystalline carbon nitride (CCN) nanosheets of poly triazine imide (PTI) embedded with melon domains are fabricated by KCl/LiCl-mediated polycondensation of dicyandiamide, the surface of which is subsequently deposited with ultrafine WO 3 nanoparticles to construct the CCN/WO 3 heterostructure with a S-scheme interface. Systematic characterizations have been conducted to reveal the compositions and structures of the S-scheme CCN/WO 3 hybrid, featuring strengthened optical capture, enhanced CO 2 adsorption and activation, attractive textural properties, as well as spatial separation and directed movement of light-triggered charge carriers. Under mild conditions, the CCN/WO 3 catalyst with optimized composition displays a high photocatalytic activity for reducing CO 2 to CO in a rate of 23.0 µmol/hr (i.e. , 2300 µmol/(hr·g)), which is about 7-fold that of pristine CCN, along with a high CO selectivity of 90.6% against H 2 formation. Moreover, it also manifests high stability and fine reusability for the CO 2 conversion reaction. The CO 2 adsorption and conversion processes on the catalyst are monitored by in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), identifying the crucial intermediates of CO 2 *−, COOH* and CO*, which integrated with the results of performance evaluation proposes the possible CO 2 reduction mechanism. [ABSTRACT FROM AUTHOR]

• Constructing extrinsic oxygen vacancies on the surface of photocatalyst were proposed. • BiOCl quantum dots were used as the source of extrinsic oxygen vacancies. • Extrinsic oxygen vacancies can act as "CO 2 and photo-generated electrons reservoirs. • Extrinsic oxygen vacancies improved photocatalytic CO 2 reduction activity of TiO 2. Constructing own oxygen vacancies in the photocatalysts is a very promising method to improve their photocatalytic CO 2 reduction activity. However, some catalysts have excellent stabilities, making it difficult for them to construct their own oxygen vacancies. To simplify the above difficulty of stable photocatalysts, constructing extrinsic oxygen vacancies on their surface as a novel idea is proposed. Here, a stable TiO 2 nanosheet is chosen as a research object, we uniformly deposited BiOCl quantum dots on their surface via a simple adsorption-deposition method. It is found that BiOCl quantum dots are able to simultaneously self-transform into defective BiOCl with many oxygen vacancies when the photocatalyst is performed photocatalytic CO 2 reduction. These extrinsic oxygen vacancies can act as "CO 2 and photo-generated electrons reservoirs" to improve CO 2 capture and accelerate the separation of photogenerated electrons and holes. For the above reasons, the modified TiO 2 showed obvious enhancement of photocatalytic CO 2 reduction compared to pristine TiO 2 and BiOCl. This work may open a new avenue to broaden the use of oxygen vacancies in the process of photocatalytic CO 2 reduction. [Display omitted] [ABSTRACT FROM AUTHOR]

The photocatalytic reduction of carbon dioxide (CO2) represents an attractive approach for solar‐energy storage and leads to the production of renewable fuels and valuable chemicals. Although some osmium (Os) photosensitizers absorb long wavelengths in the visible‐light region, a self‐photosensitized, mononuclear Os catalyst for red‐light‐driven CO2 reduction has not yet been exploited. Here, we discovered that the introduction of an Os metal to a PNNP‐type tetradentate ligand resulted in the absorption of light with longer‐wavelength (350–700 nm) and that can be applied to a panchromatic self‐photosensitized catalyst for CO2 reduction to give mainly carbon monoxide (CO) with a total turnover number (TON) of 625 under photoirradiation (λ≥400 nm). CO2 photoreduction also proceeded under irradiation with blue (λ0=405 nm), green (λ0=525 nm), or red (λ0=630 nm) light to give CO with >90 % selectivity. The quantum efficiency using red light was determined to be 12 % for the generation of CO. A catalytic mechanism is proposed based on the detection of intermediates using various spectroscopic techniques, including transient absorption, electron paramagnetic resonance, and UV/Vis spectroscopy. [ABSTRACT FROM AUTHOR]

The photocatalytic reduction of carbon dioxide (CO2) represents an attractive approach for solar‐energy storage and leads to the production of renewable fuels and valuable chemicals. Although some osmium (Os) photosensitizers absorb long wavelengths in the visible‐light region, a self‐photosensitized, mononuclear Os catalyst for red‐light‐driven CO2 reduction has not yet been exploited. Here, we discovered that the introduction of an Os metal to a PNNP‐type tetradentate ligand resulted in the absorption of light with longer‐wavelength (350–700 nm) and that can be applied to a panchromatic self‐photosensitized catalyst for CO2 reduction to give mainly carbon monoxide (CO) with a total turnover number (TON) of 625 under photoirradiation (λ≥400 nm). CO2 photoreduction also proceeded under irradiation with blue (λ0=405 nm), green (λ0=525 nm), or red (λ0=630 nm) light to give CO with >90 % selectivity. The quantum efficiency using red light was determined to be 12 % for the generation of CO. A catalytic mechanism is proposed based on the detection of intermediates using various spectroscopic techniques, including transient absorption, electron paramagnetic resonance, and UV/Vis spectroscopy. [ABSTRACT FROM AUTHOR]

Developing effective heterojunction photocatalysts that efficiently separate charge carriers and improve light-harvesting capabilities is crucial in addressing energy and environmental issues. Herein, a unique nanocomposite photocatalyst is constructed by attaching CoMn 2 O 4 nanoparticles onto 2D CdS nanosheets for H 2 production and U(VI) reduction. The optimized 2% CoMn 2 O 4 /CdS nanocomposite showcases the highest photocatalytic H 2 production efficiency, 5.8 times higher than CdS nanosheets. Additionally, the U(VI) reduction rate constant of 2% CoMn 2 O 4 /CdS is 0.0192 min−1, approximately 1.9 folds over the pristine CdS (0.0101 min−1). The exceptional photocatalytic performance toward photocatalytic H 2 evolution and U(VI) reduction reactions directly result from the electronic integration between CoMn 2 O 4 /CdS p-n heterojunction, facilitated by the efficient photoexcited charge separation. Feasible photocatalytic mechanisms are proposed through experimental analyses and theoretical calculations. This study provides a straightforward method for designing effective CdS-based heterostructured photocatalysts, contributing to the advancement of solar-to-H 2 conversion and environmental abetment. [Display omitted] • Layered CdS nanosheets have been developed to support CoMn 2 O 4 nanoparticles. • The 2% CoMn 2 O 4 /CdS exemplified the highest photocatalytic H 2 evolution. • CoMn 2 O 4 /CdS displayed an improved photocatalytic reduction of U(VI). • Possible photocatalytic mechanisms of CoMn 2 O 4 /CdS were proposed. [ABSTRACT FROM AUTHOR]

Two-dimensional mixed metal oxides have attracted attention because of their unique characteristics and diverse crystal structure. In this work, we have synthesized zinc vanadium oxide and its nanocomposite with graphitic-carbon nitride via wet-chemical and hydrothermal methods. XRD analysis unsheathe the ZnV 2 O 6 /g-C 3 N 4 for wet-chemically synthesized composite while Zn 2 V 2 O 7 /g-C 3 N 4 for hydrothermally prepared composite. The sample synthesized using the wet-chemical process, has an agglomerated structure in the FESEM micrographs while hydrothermally synthesized sample reveal porous nanosheets of the composite material. Zn 2 V 2 O 7 /g-C 3 N 4 is further characterized with XPS and HRTEM. UV–visible spectroscopy was used to describe the material's optical characteristics and the Tauc relation was used to compute the associated optical bandgap. The as-synthesized composites were assessed as an electrochemical sensing material for ascorbic acid sensing in a neutral pH analyte (PBS). Furthermore, Zn 2 V 2 O 7 /g-C 3 N 4 shows exceptional photocatalytic CO 2 reduction and yielded CH 4 as a result. As-prepared nanocomposites can be used in commercial applications for electrochemical diagnostics and photocatalytic applications. • Synthesized Zinc Vanadium Oxide and its g-C3N4 nanocomposite via wet-chemical and hydrothermal methods. • SEM and XRD analysis revealed structural differences between methods. • UV–visible spectroscopy used for optical property analysis and bandgap calculation. • Material demonstrated efficacy as a neutral pH ascorbic acid sensor. • Exceptional photocatalytic CO2 reduction, yielding methane. [ABSTRACT FROM AUTHOR]

The development of high‐performance photocatalytic systems for CO2 reduction is appealing to address energy and environmental issues, while it is challenging to avoid using toxic metals and organic sacrificial reagents. We here immobilize a family of cobalt phthalocyanine catalysts on Pb‐free halide perovskite Cs2AgBiBr6 nanosheets with delicate control on the anchors of the cobalt catalysts. Among them, the molecular hybrid photocatalyst assembled by carboxyl anchors achieves the optimal performance with an electron consumption rate of 300±13 μmol g−1 h−1 for visible‐light‐driven CO2‐to‐CO conversion coupled with water oxidation to O2, over 8 times of the unmodified Cs2AgBiBr6 (36±8 μmol g−1 h−1), also far surpassing the documented systems (<150 μmol g−1 h−1). Besides the improved intrinsic activity, electrochemical, computational, ex‐/in situ X‐ray photoelectron and X‐ray absorption spectroscopic results indicate that the electrons photogenerated at the Bi atoms of Cs2AgBiBr6 can be directionally transferred to the cobalt catalyst via the carboxyl anchors which strongly bind to the Bi atoms, substantially facilitating the interfacial electron transfer kinetics and thereby the photocatalysis. [ABSTRACT FROM AUTHOR]

Single‐metal atomic sites and vacancies can accelerate the transfer of photogenerated electrons and enhance photocatalytic performance in photocatalysis. In this study, a series of nickel hydroxide nanoboards (Ni(OH)x NBs) with different loadings of single‐atomic Ru sites (w‐SA‐Ru/Ni(OH)x) were synthesized via a photoreduction strategy. In such catalysts, single‐atomic Ru sites are anchored to the vacancies surrounding the pits. Notably, the SA‐Ru/Ni(OH)x with 0.60 wt % Ru loading (0.60‐SA‐Ru/Ni(OH)x) exhibits the highest catalytic performance (27.6 mmol g−1 h−1) during the photocatalytic reduction of CO2 (CO2RR). Either superfluous (0.64 wt %, 18.9 mmol g−1 h−1; 3.35 wt %, 9.4 mmol−1 h−1) or scarce (0.06 wt %, 15.8 mmol g−1 h−1; 0.29 wt %, 21.95 mmol g−1 h−1; 0.58 wt %, 23.4 mmol g−1 h−1) of Ru sites have negative effect on its catalytic properties. Density functional theory (DFT) calculations combined with experimental results revealed that CO2 can be adsorbed in the pits; single‐atomic Ru sites can help with the conversion of as‐adsorbed CO2 and lower the energy of *COOH formation accelerating the reaction; the excessive single‐atomic Ru sites occupy vacancies that retard the completion of CO2RR. [ABSTRACT FROM AUTHOR]

Considering that CO2 reduction is mostly a multielectron reaction, it is necessary for the photocatalysts to integrate multiple catalytic sites and cooperate synergistically to achieve efficient photocatalytic CO2 reduction to various products, such as C2 hydrocarbons. Herein, through crystal engineering, we designed and constructed a metal–organic framework‐derived Zr/Ti bimetallic oxide solid solution support, which was confirmed by X‐ray diffraction, electron microscopy and X‐ray absorption spectroscopy. After anchoring Au nanoparticles, the composite photocatalyst exhibited excellent performances toward photocatalytic CO2 reduction to syngas (H2 and CO production rates of 271.6 and 260.6 μmol g−1 h−1) and even C2 hydrocarbons (C2H4 and C2H6 production rates of 6.80 and 4.05 μmol g−1 h−1). According to the control experiments and theoretical calculations, the strong interaction between bimetallic oxide solid solution support and Au nanoparticles was found to be beneficial for binding intermediates and reducing CO2 reduction, highlighting the synergy effect of the catalytic system with multiple active sites. [ABSTRACT FROM AUTHOR]