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This study reports novel noble-metal-free photocatalytic composites containing CoP nanoparticles modified Mn-doped CdS (MCS) nanorods for producing H 2 by water splitting. MCS nanorods are prepared with various molar ratios of Cd to Mn via a solvothermal method. Compared to other MCS samples, the MCS-8:3 sample with exceptional crystallinity and shorter radial transfer paths displays the highest H 2 production rate, which is used for further modification. To mitigate the recombination of electrons and holes, CoP nanoparticles owning metallic properties are deposited onto the surface of MCS-8:3 as cocatalysts using a deposition–phosphorization method. The influence of the amounts of CoP on the morphology and H 2 production rates was investigated. The testing results indicate that MCS/CoP-7% exhibits significantly enhanced photocatalytic H 2 production rate of 40.5 mmol/g/h. This value is 4.7 times more than that of MCS-8:3, which is higher than most of the reported MCS-based catalysts. The optical and electrochemical experiments reveal that the established heterojunctions between MCS and CoP enable to improve the average charge lifetime, the separation and transfer of photogenerated charge. Furthermore, the band structures of the composites are also estimated. Combining with the XPS results and band structure, the enhanced photocatalytic performances can be attributed to the Schottky heterojunctions with the efficient electron-transfer pathway between MCS and CoP are proposed. [Display omitted] • The amounts of Mn in CdS lattice and CoP on its surface are optimized. • MCS/CoP-7% shows the high H 2 production rates of 40.5 mmol/g/h. • Schottky heterojunction is formed between MCS and CoP. • The high performance is due to low recombination rates and long carrier lifetime. [ABSTRACT FROM AUTHOR]

Of current interest is visible-light activated g-C3N4, owing to its unique physicochemical properties for the photocatalytic H2 production and pollutant remediation. In this research, the synthetic procedures, physicochemical properties, and major approaches to overcome the intrinsic drawbacks of g-C3N4 are reviewed. Of different synthesis procedures for GCN, thermal polymerization is recommended with advantages such as simplicity, economic, and high yield. Element doping, as a facile method, can modify g-C3N4 structure and improve its performance in the photocatalytic evolution of H2 which is significantly increased from 208 µmol h−1 g−1 for bare g-C3N4 to 5128 µmol h−1 g−1 for P-doped g-C3N4. Ammonium salts can be effectively used for the synthesis of g-C3N4 nanosheets and element doping simultaneously. Vacancy defect plays an important role in the improvement of the photocatalytic activity. Compared to custom photocatalysis and electrocatalysis, photoelectrocatalysis is highly promising for pollutant decontamination due to the effective separation of charge carriers. [ABSTRACT FROM AUTHOR]

Cadmium sulfide (CdS) based heterojunctions, including type‐II, Z‐scheme, and S‐scheme systems emerged as promising materials for augmenting photocatalytic hydrogen (H2) generation from water splitting. This review offers an exclusive highlight of their fundamental principles, synthesis routes, charge transfer mechanisms, and performance properties in improving H2 production. We overview the crucial roles of Type‐II heterojunctions in enhancing charge separation, Z‐scheme heterojunctions in promoting redox potentials to reduce electron‐hole (e−/h+) pairs recombination, and S‐scheme heterojunctions in combining the merits of both type‐II and Z‐scheme frameworks to obtain highly efficient H2 production. The importance of this review is demonstrated by its thorough comparison of these three configurations, presenting valuable insights into their special contributions and capability for augmenting photocatalytic H2 activity. Additionally, key challenges and prospects in the practical applications of CdS‐based heterojunctions are addressed, which provides a comprehensive route for emerging research in achieving sustainable energy goals. [ABSTRACT FROM AUTHOR]

Photocatalytic water splitting is considered as one of the most promising technologies for hydrogen production. A novel 2D/2D/2D ZnCo2O4/g‐C3N4/Ti3C2 (ZCO/CN/TiC) nanocomposite was synthesized through a facile thermal method for efficient photocatalytic H2 production under visible light. This multi‐heterojunction system displayed an efficient performance with higher H2 production rates compared to single catalysts. The experimental results revealed a hydrogen production rate of 1465 µmol g−1 for the ZCO/CN/TiC ternary composite after 4 h of light irradiation, which is about 3.8 and 2.5 times higher than that of g‐C3N4 and g‐C3N4/Ti3C2, respectively. This significant enhancement is mainly attributed to the efficient charge transfer within the constructed heterojunction system and due to the presence of MXene (Ti3C2), which acted as a solid electron mediator to suppress the charge recombination rate. Both the type and the amount of used sacrificial agent have exhibited a significant effect on the H2 production rate. The ZCO/CN/TiC ternary nanocomposite has also displayed the best quantum yield (QY = 1.316). The newly developed structured photocatalyst would provide a promising approach for the construction of easyprepared and noble‐metal‐free photocatalysts for the application of clean and sustainable fuel production. [ABSTRACT FROM AUTHOR]

Electron transfer mechanism of C-Ni 5 P 4 /CdS under visible light irradiation. [Display omitted] The capacitance of a co-catalyst can be likened to a "double-edged sword". Α co-catalysts with high capacitance can store photoexcited electrons, thereby facilitating charge separation within the host catalyst. However, this property simultaneously restricts electron release. Both effects are enhanced with an increasing capacitance value, implying that excessively high capacitance can significantly hinder the photocatalytic hydrogen (H 2) production reaction. Herein, we have designed a metal-organic framework (MOF) -derived carbon-coated nickel phosphide (C-Ni 5 P 4) as the co-catalyst of cadmium sulfide (CdS). When C-Ni 5 P 4 and CdS are closely interconnected, electrons spontaneously migrate from CdS to C-Ni 5 P 4 under irradiation due to the higher work function (WF) of C-Ni 5 P 4 compared to CdS. Most importantly, although the WF of C-Ni 5 P 4 is 0.1 eV lower than that of Ni 5 P 4 , its specific capacitance (1.2 mF/cm2) is also lower than that of Ni 5 P 4 (1.3 mF/cm2). This difference dramatically promotes electron release. Thereby exerting a strong positive effect on capacitance catalysis. Therefore, 7% C-Ni 5 P 4 /CdS exhibits exceptional cyclic stability and has a remarkably high activity level of 12283 μmol/h/g and 3.8 times as many as 3.0 %Ni 5 P 4 /CdS. This study provides a theoretical basis for the advancement of photocatalysts with high efficiency in H 2 production and is expected to be applied in other fields of photocatalysis. [ABSTRACT FROM AUTHOR]

Adjusting the interfacial transport efficiency of photogenerated electrons and the free energy of hydrogen adsorption through interface engineering is an effective means of improving the photocatalytic activity of semiconductor photocatalysts. Herein, hollow ZnS/NiS nanocages with ohmic contacts containing Zn vacancy (VZn-ZnS/NiS) are synthesized using ZIF-8 as templates. An internal electric field is constructed by Fermi level flattening to form ohmic contacts, which increase donor density and accelerate electron transport at the VZn-ZnS/NiS interface. The experimental and DFT results show that the tight interface and VZn can rearrange electrons, resulting in a higher charge density at the interface, and optimizing the Gibbs free energy of hydrogen adsorption. The optimal hydrogen production activity of VZn-ZnS/NiS is 10,636 μmol h−1 g−1, which is 31.9 times that of VZn-ZnS. This study provides an idea for constructing sulfide heterojunctions with ohmic contacts and defects to achieve efficient photocatalytic hydrogen production.

[Display omitted] • A chemically bonded 0D/2D Au/ZIS-V ohmic junction was prepared. • Synergistic effect of built-in electric field, Au-S bonds and Zn vacancies on dual-function photocatalysis. • Au/ZIS-V is suitable for photocatalytic selective alcohol oxidation coupled with H 2 production and CO 2 reduction. • The thermodynamics and kinetics of photoredox were simultaneously improved. • The utilization factor of photoexcited holes to electrons can reach up to 0.99. Combining photocatalytic reduction with organic synthetic oxidation in the same photocatalytic redox system can effectively utilize photoexcited electrons and holes from solar to chemical energy. Here, we stabilized 0D Au clusters on the substrate surface of Zn vacancies modified 2D ZnIn 2 S 4 (ZIS-V) nanosheets by chemically bonding Au-S interaction, forming surfactant functionalized Au/ZIS-V photocatalyst, which can not only synergistic accelerate the selective oxidation of phenylcarbinol to value-added products coupled with clean energy hydrogen production but also further drive photocatalytic CO 2 -to-CO conversion. An internal electric field of Au/ZIS-V ohmic junction and Zn vacancies synchronously promote the photoexcited charge carrier separation and transfer to optimized active sites for redox reactions. Compared with CO 2 reduction in water and the pristine ZnIn 2 S 4 , the reaction thermodynamics and kinetics of CO 2 reduction over the Au/ZIS-V were simultaneously improved about 11.09 and 45.51 times, respectively. Moreover, the photocatalytic redox mechanisms were also profoundly studied by 13CO 2 isotope tracing tests, in situ electron paramagnetic resonance (in situ EPR), in situ X-ray photoelectron spectroscopy (in situ XPS), in situ diffuse reflection infrared Fourier transform spectroscopy (in situ DRIFTS) and density functional theory (DFT) characterizations, etc. These results demonstrate the advantages of vacancies coupled with metal clusters in the synergetic enhancement of photocatalytic redox performance and have great potential applications in a wide range of environments and energy. [ABSTRACT FROM AUTHOR]

Photocatalytic hydrogen production is a promising renewable energy process. CdS is a widely used photocatalyst; however, the photocorrosion problem causing the low stability and fast charge recombination problem causing the low photocatalytic activity are also well-known. To prevent the stability problem, CdxZn1-xS which has tunable optical properties has become forward. MoS2 is used as an additive to semiconductor photocatalysts due to its wide contact interface, inhibition of charge recombination, low cost, high reactivity for H2 evolution reaction, and enhancement of visible light response. In this study, CdxZn1-xS/MoS2 was synthesized in an uniformly distributed nanocomposite form by solvothermal method using 1,3-diaminopropane for the first time. The characterization of the photocatalysts was performed with XRD, UV-vis DRS, TEM and electrochemical measurements. CdxZn1-xS/MoS2 photocatalysts were tested for hydrogen production under solar light. A full factor design was carried out via Minitab 19 to investigate the factors affecting the produced hydrogen amount. Cd/Zn ratio, MoS2 content, and photocatalyst loading were studied. Photocatalytic hydrogen production results were examined by analysis of variance and interpretation plots showed that the maximum hydrogen production would be obtained with 10 mg photocatalyst loading by CdxZn1-xS/MoS2 with Cd/Zn ratio between 0.5/0.5 and 0.7/0.3, and MoS2 content 2–4%. [ABSTRACT FROM AUTHOR]

Photocatalytic hydrogen production by semiconductors is an optimal path to achieve solar energy conversion. In this work, Cu2O/ZnFe2O4 type II heterostructure is composed of ZnFe2O4 nanoparticles loaded on the surface of Cu2O microspheres, the photocatalytic hydrogen evolution performance is studied. Under the irradiation 5 h of 5 w LED lamp, the hydrogen production of Cu2O/ZnFe2O4 composites was 30.8 and 12.7 times higher than pure Cu2O and pure ZnFe2O4, respectively. In addition, after four cycles of experiments for 20 h, the hydrogen production is still maintained at 67.4% of the initial activity, indicating the relatively stable hydrogen evolution activity of the composite material. The electron transfer mechanism of the photocatalyst was confirmed through the utilization of density functional theory (DFT) and in-situ irradiation X-ray photoelectron spectroscopy. The effective interfacial contact between Cu2O and ZnFe2O4 nanoparticles forms a type II heterojunction, which makes the effective separation of photogenerated charges, facilitates the reduction of protons to H2, and achieves efficient hydrogen production. This work presents a strategy for simple design and fabrication of highly efficient composite photocatalysts. [ABSTRACT FROM AUTHOR]

Dibenzothiophene-S,S-dioxide (BTDO) is one of the cutting-edge electron-acceptor monomers for designing conjugated polymer based organic materials toward photocatalytic H 2 production from water. Normally, structure design of BTDO containing donor-acceptor (D-A) polymer photocatalyst mainly focuses on screening electron-donor motifs, the importance of modification on BTDO molecular toward improving charge carrier separation and photocatalytic performance is always ignored. Herein, a novel thienyl-fused BTDO building block (BTDO-DT) is prepared and utilized to synthesize B-BTDO-DT polymer photocatalyst by Sonogashira-Hagihara cross-coupling polycondensation using 1,4-Diethynylbenzene (B) and BTDO-DT as monomers. Experimental and density functional theory (DFT) calculation results demonstrate that modification of BTDO by thiophene not only enlarges light absorption region and promotes photogenerated e−/h+ separation, but also decreases H atom adsorption free energy (ΔG H*) on oxygen atom in the O S O group. As a result, B-BTDO-DT exhibits an outstanding visible light induced photocatalytic H 2 production rate of 156.6 μmol h−1 using 30 mg catalyst without Pt cocatalyst, which is 4.5 times higher than that of B-BTDO. And the H 2 production rate of B-BTDO-DT is further improved to be 259.8 μmol h−1 with 2.0 wt% Pt as co-catalyst. The present work may open a new direction for the design of conjugated polymer based photocatalysts with high photocatalytic activities. A novel thienyl-fused Dibenzothiophene-S,S-dioxide (BTDO) building block (BTDO-DT) is prepared and utilized to synthesize B-BTDO-DT polymer photocatalyst, which exhibits wider visible light absorption region, quicker photogenerated e−/h+ separation and smaller H atom adsorption free energy (ΔG H*) when compared with B-BDTO polymer, resulting in 4.5 times improvement on photocatalytic H 2 production performance. [Display omitted] • Dibenzothiophene-S,S-dioxide is fused by thiophene to prepare B-BTDO-DT polymer. • B-BTDO-DT exhibits narrower band-gap and quicker e−/h+ separation than B-BTDO. • Photocatalytic H 2 production rate of B-BTDO-DT is 4.5 times higher than B-BTDO. [ABSTRACT FROM AUTHOR]

We present a novel approach for the room temperature synthesis and integration of Ru nanoparticles into a Z-scheme heterojunction comprising graphitic carbon nitride (CN) and zeolitic imidazolate framework-8 (ZIF-8). This heterojunction demonstrates outstanding efficiency in sunlight-driven hydrogen (H 2) generation via water splitting. Various structural and spectroscopic analyses elucidate Ru nanoparticles' successful incorporation and synergistic effects within the CN/ZIF-8 heterojunction because the decrease in interplanar spacing due to π-π stacking interactions between aromatic rings of tri- s -triazine in CN and imidazole rings in ZIF-8. The Z-scheme configuration facilitates efficient charge separation and promotes H 2 production. Additionally, Ru nanoparticles offer alternative electron transfer pathways, enhancing carrier separation and prolonging the lifespan of photoinduced charges compared to CN and ZIF-8 alone. Notably, RZCN-2 heterojunction exhibited significantly enhanced hydrogen production, reaching 5245 μmol g−1 h−1. By analyzing work functions and energy band structures, we demonstrate that the strong interfacial electric fields across the Z-scheme heterojunction effectively mitigate the recombination of photogenerated charges while maintaining the necessary redox capacity for efficient H 2 production. The room temperature synthesis and integration of Ru nanoparticles provide a practical and effective strategy for optimizing photocatalytic activity and promoting sustainable energy conversion, thereby advancing photocatalytic technologies. • Room temperature preparation and incorporation of Ru NP into CN, and ZIF-8 to construct Z-scheme heterojunction. • Loading Ru NP enhanced NIR light absorbance for better HER. • Narrow VB energy of CN, and ZIF-8 synergistically built electric field among RZCN-2 heterojunction. • RZCN-2 photocatalyst exhibits large surface area and long decay time for photoexcited charged carriers. • The optimal RZCN-2 demonstrated outstanding H 2 generation up to 5245 μmolg−1h−1. [ABSTRACT FROM AUTHOR]

Solar-driven water splitting for photocatalytic hydrogen evolution is considered a highly promising and cost-effective solution to achieve a stable renewable energy supply. However, the sluggish kinetics of electron-hole pairs' separation poses challenges in attaining satisfactory hydrogen production efficiency. Herein, we synthesized the exceptional performance of highly crystalline C3N5 (HC-C3N5) nanosheet as a photocatalyst, demonstrating a remarkable hydrogen evolution rate of 3.01 mmol h-1 g-1, which surpasses that of bulk C3N5 (B-C3N5) by a factor of 3.27. Experimental and theoretical analyses reveal that HC-C3N5 nanosheets exhibit intriguing macroscopic photoinduced color changes, effectively broadening the absorption spectrum and significantly enhancing the generation of excitons. Besides, the cyano groups in HC-C3N5 efficiently captures and converts photoexcited electrons into bound states, thereby prolonging their lifetimes and effectively separating electrons and holes into catalytically active regions. This research provides valuable insights into the establishment of bound electronic states for developing efficient photocatalysts. [ABSTRACT FROM AUTHOR]

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A solar-driven hydrogen production process using a graphitic carbon nitride (CN) photocatalyst is an ideal future clean energy source. However, hydrogen production efficiency in the CN photocatalytic system is still limited due to rapid electron–hole (e−/h+) recombination. Herein, we report an efficient photocatalyst BCN-TPP by introducing 2,4,6-triphenylpyrylium (TPP) to boron-doped nitrogen-deficient carbon nitride (BCN) through π–π interaction and π–cation interaction. The as-prepared photocatalyst shows increased visible light absorption and narrow band gap, enhancing the separation of photogenerated e–/h+ pairs. TPP acts as a redox mediator under visible light excitation that can accept electrons from BCN, and then transfer them to the Pt cocatalyst. Photoluminescence (PL), electron paramagnetic resonance (EPR), and other electrochemical studies have exhibited that introducing a TPP mediator significantly enhances photogenerated charge carrier separation. BCN-TPP (10 wt % TPP) nanostructures achieved the photocatalytic H2 generation rate of 110.33 μmol h–1 at visible light illumination (λ ≥ 420 nm), which is 9.59 times higher than that of pristine C3N4 (11.50 μmol h–1) and the apparent quantum efficiency (AQE) of 6.03% at 450 nm. Moreover, BCN-TPP shows the stability of H2 evolution over 4 cycles without any significant decline. This study represents an approach for designing efficient nanoheterostructured photocatalysts for hydrogen production from water splitting. [ABSTRACT FROM AUTHOR]

Organic–inorganic halide perovskites have shown great potential for the conversion of solar energy to hydrogen fuel via photocatalytic reaction due to their excellent optoelectronic properties. However, one of the biggest challenges for organic–inorganic halide perovskite materials in photocatalytic hydrogen evolution reaction (HER) lies in the serious recombination of photogenerated electron and hole pairs. Herein, we reported that the coupling of nickel phosphide (Ni2P) nanoparticles with methylammonium lead halide (MAPbI3) perovskite can significantly enhance the photocatalytic H2 evolution performance of MAPbI3. We found that Ni2P coupling can promote the electron exaction from MAPbI3, thereby accelerating the charge transfer and retarding the charge recombination. Moreover, Ni2P particles exhibited good electrocatalytic activity for the HER. Consequently, the Ni2P/MAPbI3 composite exhibited ca. 459 times higher activity than the parent MAPbI3 in photocatalytic HI splitting reaction. Moreover, the Ni2P/MAPbI3 composite exhibited excellent stability during cycling tests. This work demonstrated the potential of using Ni2P as non-noble metal-based co-catalyst to promote the photocatalytic performance of organic–inorganic halide perovskite. [ABSTRACT FROM AUTHOR]

Single - atom catalysts (SACs) have attracted extensive attention because of their high atomic utilization and superior catalytic activity. Herein, single - atom Co has anchored on the β - ketoenamine - linked covalent organic framework (Tp-Tta COF) pores and used for remarkable photocatalytic hydrogen(H 2) production under Ultraviolet – Visible light (UV – Vis light) irradiation. The single - atom Co is visualized by the aberration - corrected high - angle annular dark - field scanning transmission electron microscopy (AC HAADF - STEM), and the C 3 – Co – N 1 coordination structure is demonstrated by X - ray absorption fine structure (XAFS) measurements. The modified Co 0.4 -SAC/Tp-Tta COF shows a high photocatalytic H 2 production of 1798.5 μmol g−1 h−1 and the Apparent quantum yield(AQY) is 3.02% at 420 nm. The improvement of the activity and stability of the photocatalyst is mainly attributed to the incorporation of Co single-atom that boosts the separation efficiency of photogenerated electron-hole pair and provides well - dispersed active sites. This study provides valuable insights into the development of UV–Vis light-responsive photocatalysts at the atomic level. Single-atom cobalt (Co) was anchored on the β-ketoenamine-linked covalent organic framework (Tp-Tta COF) pores to form C 3 –Co–N 1 active sites, and the Co 0.4 -SAC/Tp-Tta COF showed excellent H 2 evolution performance under UV–Vis-light irradiation (1798.5 μmol g−1 h−1). [Display omitted] • Single-atom Co stably anchored on Tp-Tta COF to form C 3 –Co–N 1 coordination structure. • Co 0.4 -SAC/Tp-Tta COF exhibited a high photocatalytic H 2 evolution rate of up to 1798.5 μmol g−1 h−1, which was 76 times more active than that of bare Tp-Tta COF. • The Co 0.4 -SAC/Tp-Tta COF holds stable H 2 production over 4 cycles with AQY is 3.02% at 420 nm. [ABSTRACT FROM AUTHOR]

It is expected that the activity of photocatalysts can remain the same or decrease as little as possible in photocatalysis reaction. Herein, for the first time, a self‐accelerating H2 production activity in a noble‐metal‐free Cu2O/TpPa‐2‐COF photocatalyst is reported. It shows a beginning H2 production rate of 4.41 mmol h−1 g−1 under visible light illuminance, while the activity kept increasing to 27.27 mmol h−1 g−1 after 25 h reaction, which is 6.2 times higher than the beginning activity and reaches a record high. It is confirmed that part of Cu2O in Cu2O/TpPa‐2‐COF in situ transformed to Cu0 in photocatalytic reaction, which acting as cocatalyst promotes the separation of photogenerated charge carriers. Further density functional theory calculations demonstrate that the Schottky barrier height of Cu‐Cu2O (111) interface is much smaller than that of Pt‐Cu2O (111), supporting its more efficient effect than that with Pt as cocatalyst. [ABSTRACT FROM AUTHOR]

The combination of controlled defects and atom-dispersed co-catalyst construction is an effective means of improving the photocatalytic performance of catalysts. Here, we grafted a low content of atomically dispersed Mo onto the TiO 2 surface and simultaneously introduced the Ti3+ and V O defects, obtaining a low-content atomically dispersed Mo-grafted defective TiO 2 (Mo/TiO 2 –H) photocatalyst. The Mo/TiO 2 –H exhibited significantly improved photocatalytic hydrogen production activity by utilizing the synergistic interaction between atomically dispersed Mo and defects. The hydrogen production rate of Mo 0.36 /TiO 2 –H with only 0.36% Mo increased by 11.17-fold compared to the pristine TiO 2 and achieved 228.98 mmol per g Mo. This strategy can be also used to synthesize low-content atomically dispersed various metal (Mo, Ni, Ru, and Co)-grafted defect-containing TiO 2 photocatalysts. The excellent photocatalytic activity of the non-noble metal Ni and Mo-modified TiO 2 suggests that the use of low-content non-noble metal single-atom catalysts can significantly reduce the cost of renewable solar hydrogen production. [Display omitted] • Low content atomically dispersed Mo grafted defective TiO 2 are prepared. • H 2 production rate of Mo 0.36 /TiO 2 –H increased by 11.17-fold compared to TiO 2. • Synergistic effects of defects and atomically dispersed Mo promote charge transfer. • Atomically dispersed Mo acts as an active site for proton reduction. • Ni, Ru, and Co-grafted defective TiO 2 can be prepared by the same method. [ABSTRACT FROM AUTHOR]

[Display omitted] In this work, we report a series of noble metal (Ag, Au, Pt, etc.) sulfides that act as co-catalysts anchoring on CdS nanorods (NRs) obtained via a cation exchange strategy to promote photocatalytic hydrogen evolution. CdS NRs are first generated via a hydrothermal routine, noble metal sulfides are then in-situ grown on CdS NRs by a cation exchange method. CdS/Ag 2 S, CdS/Au 2 S and CdS/PtS NRs show improved hydrogen production rates (2506.88, 1513.17 and 1004.54 μmol g−1h−1, respectively), approximately 18, 11 and 7 times higher than CdS NRs (138.27 μmol g−1h−1). Among CdS/noble metal sulfide NRs, CdS/Ag 2 S NRs present the best H 2 production performance. The apparent quantum efficiency (AQE) of CdS/Ag 2 S NRs achieves 3.11 % at λ = 370 nm. The improved photocatalytic performance of CdS/noble metal sulfide NRs dues to the following points: i) Noble metal sulfides on CdS NRs are beneficial for elevating light-absorbing and light-utilizing capacities, contributing to generating more photoexcited charges; ii) Noble metal sulfides are in-situ grown on CdS NRs as electron acceptors by a cation exchange method, thus the photoexcited electrons generated by CdS NRs rapidly migrate to the surface of noble metal sulfides, successfully accelerating the carriers separation efficiency. This series of noble metal sulfides acting as co-catalysts anchoring on CdS NRs offer new insights into the construction principles of high-performance photocatalytic hydrogen evolution catalysts. [ABSTRACT FROM AUTHOR]

Here, lithium ions inserted crystalline carbon nitrides (LCCN) with different defect concentrations are prepared by elaborately regulating the mass transfer process in thermal polymerization. It is revealed that there is no conventional exciton–polarons‐induced exciton dissociation mechanism in LCCN due to the weak coupling between excitons and phonons. On the contrary, excitons continue to trap/detrap through defect‐induced traps, which weakens the Coulomb force between electron–hole pairs, thereby accelerating exciton dissociation. It is worth emphasizing that this is the first systematic research on the exciton dissociation characteristics and photocatalytic activity of LCCN of poly(heptazine imide) structure. A strategy of assisting exciton dissociation through defect‐induced traps to address the inherently high exciton binding energy and low exciton dissociation efficiency issues in polymer photocatalysts is proposed. [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]

Donor-acceptor conjugated polymers have received significant attention as the most promising photocatalysts for efficient photocatalytic hydrogen production (PHP). Nonetheless, achieving high photocatalytic PHP performance relies on molecular framework design and the judicious selection of different structural units. Herein, benzotrithiophene (BTT) and triazine derivatives were used as the basic units of organic polymers, and two conjugated porous polymers (CPPs) named as CP1 and CP2 were successfully synthesized by Stille coupling reaction. Compared with benzene as the linkage unit of triazine, it is evident that the incorporation of the thiophene unit in CP2 broadens its light response range, and promotes the generation of electrons/holes induced by light. Density functional theory (DFT) calculations and femtosecond transient absorption(fs-TA) spectroscopy reveal that CP2 effectively inhibits the photogenerated electron-hole pair recombination and promotes carrier transport. Remarkably, CP2 with Pt co-catalyst exhibited a notably superior PHP performance compared with that of CP1 polymer, which achieved an impressive hydrogen evolution rate (HER) of 21702.4 μmol/g/h, surpassing CP1 by approximately 3.7 times. This work provides a new tactic for enhancing the intrinsic PHP activity and reveals the underlying mechanism for the enhanced photocatalytic activity by regulating the different structural units of the donor-acceptor conjugated polymers. [Display omitted] • Two conjugated porous polymers were constructed based on benzotrithiophen and triazine derivatives. • Polymers CP1 and CP2 were prepared from benzene and thiophene linked triazine derivatives, respectively. • The different linkage units contribute to the great difference in photocatalytic performance. • CP2 exhibited an ultrahigh hydrogen evolution rate 21702.4 μmol/g/h. • The thiophene unit in CP2 suppress recombination of photo-induced charge carriers and promote transport. [ABSTRACT FROM AUTHOR]

Synergetic photocatalytic H2 production by organic dye photodegradation is always a goal. However, the related research has been hindered due to the uncontrollability of this process. This study prepares the ZnO/Bi-QDs/BiOBr photocatalyst, and the hole (h+) aggregation phase (ZnO) is constructed into a lamellar porous structure to improve its adsorption capacity for dyes based on the energy level structure of the composite. By this method, the reactive groups used for photodegradation of dyes are controlled to h+ and •OH, e– is used for photocatalytic H2 production, and the synergistic effect of dye photodegradation and photocatalytic H2 production is realized. Under the action of this photocatalyst and visible light, rhodamine B (RhB) is completely degraded in 8 min, the time can be reduced to 2 min when pH is 5, and it can realize the complete degradation of RhB in 120 min under natural sunlight. The H2 production rate reaches 1678 μmol·g–1·h–1 in RhB (h+ scavenger) aqueous solution under visible light. This study provides an effective method and design idea for the design of photocatalysts with photocatalytic H2 production during the photodegradation of organic dyes. [ABSTRACT FROM AUTHOR]

Light‐driven hydrogen production from biomass derivatives offers a path towards carbon neutrality. It is often however operated with the limitations of sluggish kinetics and severe coking. Herein, a disruptive air‐promoted strategy is explored for efficient and durable light‐driven hydrogen production from ethanol over a core/shell Cr2O3@GaN nanoarchitecture. The correlative computational and experimental investigations show ethanol is energetically favorable to be adsorbed on the Cr2O3@GaN interface, followed by dehydrogenation toward acetaldehyde and protons by photoexcited holes. The released protons are then consumed for H2 evolution by photogenerated electrons. Afterward, O2 can be evolved into active oxygen species and promote the deprotonation and C−C cleavage of the key C2 intermediate, thus significantly lowering the reaction energy barrier of hydrogen evolution and removing the carbon residual with inhibited overoxidation. Consequently, hydrogen is produced at a high rate of 76.9 mole H2 per gram Cr2O3@GaN per hour by only feeding ethanol, air, and light, leading to the achievement of a turnover number of 266,943,000 mole H2 per mole Cr2O3 over a long‐term operation of 180 hours. Notably, an unprecedented light‐to‐hydrogen efficiency of 17.6 % is achieved under concentrated light illumination. The simultaneous generation of aldehyde from ethanol dehydrogenation enables the process more economically promising. [ABSTRACT FROM AUTHOR]

Here, we demonstrate a new type of S and C co-doped g-C 3 N 4 hexagonal ultra-thin tubular composite photocatalyst with extraordinary photocatalytic activity toward H 2 production from H 2 O with visible light irradiation. The S and C co-doped g-C 3 N 4 hexagonal ultra-thin tubular composite photocatalyst was prepared through a precursor calcinating process at 520 °C in a nitrogen atmosphere. The precursor was obtained through a supramolecular self-assembly strategy using melamine and thiolactic acid as raw materials by a crosslinking process of sulfhydryl and carboxyl groups. Benefiting from the synergetic effects of elements doping and the ultra-thin tubular morphology, the obtained S and C co-doped g-C 3 N 4 hexagonal ultra-thin tubular composite photocatalyst exhibits a highly efficient photocatalytic activity toward H 2 production from H 2 O with the irradiation of visible light, which is 24 times higher than that of the pristine g-C 3 N 4. The optimized apparent quantum yield was demonstrated to be around 9.56 %. A possible photocatalytic mechanism relating to H 2 evolution from H 2 O with visible light irradiation concerning the prepared S and C co-doped g-C 3 N 4 hexagonal ultra-thin tubular composite photocatalyst was proposed. The current study might provide valuable insights for the design and synthesis of highly efficient photocatalysts for hydrogen production using solar energy. Benefiting from the synergetic effects of elements doping and the ultra-thin tubular morphology, the obtained S and C co-doped graphite phase carbon nitride photocatalyst with an ultra-thin microtube morphology exhibits a remarkable photocatalytic activity toward H 2 production from H 2 O with the irradiation of visible light. [Display omitted] • The S–C-g-C 3 N 4 composite was synthesized via a precursor thermal polymerization. • The precursor was obtained through a supramolecular self-assembly strategy. • The S–C-g-C 3 N 4 composite photocatalyst shows a highly efficient catalytic activity. • The photocatalytic mechanism has been tentatively proposed. [ABSTRACT FROM AUTHOR]

Ni3Si2O5(OH)4 rods (NS) were synthesized via a hydrothermal method, employing natural wollastonite as a template. The hierarchical Ni3Si2O5(OH)4 rods exhibited vertically oriented nanosheets, resulting in a substantial increase in the specific surface area (from 2.24 m2/g to 178.4 m2/g). Subsequently, a CdS/Ni3Si2O5(OH)4 composite photocatalyst (CdS/NS) was prepared using a chemical deposition method. CdS was uniformly loaded onto the surface of the Ni3Si2O5(OH)4 nanosheets, successfully forming a heterojunction with Ni3Si2O5(OH)4. The CdS/NS photocatalyst in the presence of lactic acid as a sacrificial agent demonstrated an impressive H2 production rate of 4.05 mmol h−1 g−1, around 40 times higher than pure CdS. The photocorrosion of CdS was effectively solved after loading. After four cycles, the performance of CdS/NS remained stable, showing the potential for sustainable applications. After photoexcitation, electrons moved from Ni3Si2O5(OH)4 to the valence band of CdS, where they interacted with the holes via an enhanced interface contact. Simultaneously, electrons in CdS transitioned to its conduction band, facilitating hydrogenation. The enhanced performance was attributed to the improved CdS dispersion by Ni3Si2O5(OH)4 loading and efficient photogenerated carrier separation through the heterojunction formation. This work provides new perspectives for broadening the applications of mineral materials and developing heterojunction photocatalysts with good dispersibility and recyclability. [ABSTRACT FROM AUTHOR]

Solar-driven water splitting for photocatalytic hydrogen evolution is considered a highly promising and cost-effective solution to achieve a stable renewable energy supply. However, the sluggish kinetics of electron-hole pairs’ separation poses challenges in attaining satisfactory hydrogen production efficiency. Herein, we synthesized the exceptional performance of highly crystalline C3N5 (HC–C3N5) nanosheet as a photocatalyst, demonstrating a remarkable hydrogen evolution rate of 3.01 ​mmol ​h−1 ​g−1, which surpasses that of bulk C3N5 (B–C3N5) by a factor of 3.27. Experimental and theoretical analyses reveal that HC-C3N5 nanosheets exhibit intriguing macroscopic photoinduced color changes, effectively broadening the absorption spectrum and significantly enhancing the generation of excitons. Besides, the cyano groups in HC-C3N5 efficiently captures and converts photoexcited electrons into bound states, thereby prolonging their lifetimes and effectively separating electrons and holes into catalytically active regions. This research provides valuable insights into the establishment of bound electronic states for developing efficient photocatalysts.

Green hydrogen has emerged as a critical component in the upcoming renewable energy landscape. Enzyme architecture remains the prime inspiration for designing environment-friendly, efficient, and economical H 2 production catalysts from water. The strategic incorporation of peripheral protic functionalities around synthetic metal cores specifically impacts the electrocatalytic H 2 evolution reactivity. Here, we have deployed a click chemistry methodology to incorporate a 1,2,3-triazole linker in either meta vs. para position to connect a cobaloxime core with nucleobase adenine. The variation in specific positioning (meta vs. para) of the linker creates two isomeric ligands and their corresponding cobaloxime derivatives. The trifunctional ligand motif positively influences the reactivity of the cobaloximes, as the para -substituted complex produces H 2 at a rate of 5350 s−1 with an overpotential <350 mV in near-neutral aqueous conditions. The meta -substituted complex displayed relatively slower catalysis (rate 3700 s−1), albeit with similar energy efficiency under analogous conditions. These robust catalysts also demonstrated substantial H 2 production from water under photocatalytic conditions with an appreciable turnover number (TON) of 150 and 100 for the par a- and meta -substituted complexes, respectively. The complementary electrochemical and spectroscopic techniques indicate the designed ligand's dual effect (electronic and peripheral) on the catalytic reactivity, where the para-substituted pyridinyl ligand displayed better reactivity than the meta -derivative. [Display omitted] • A new strategy for the inclusion of peripheral protic features on a cobaloxime derivatives. • Rapid and energy-efficient Hydrogen Production. • Nucleobase as a component for bio-inspired hydrogen production catalyst design. • Dual active catalyst: hydrogen production in both electro and photocatalytic conditions. [ABSTRACT FROM AUTHOR]

In this study, the effect of Co doping in CsPbBr 3 perovskite on phase transition and photocatalytic hydrogen production under a magnetic field was studied. Square CsPbBr 3 nanoparticles with a dimension of 30–40 nm have been synthesized by the hot injection method. Rietveld refinement on the XRD pattern revealed the phase transition from cubic to orthorhombic after Co doping. The addition of 3%Co to CsPbBr 3 resulted in a significant hydrogen production capacity of 3500 μmol/g in 4 h, with the maximum hydrogen production rate of 1042.11 μmol/g·h in the first hour, which was 1.80 times the maximum hydrogen production rate of bare CsPbBr 3 (581.66 μmol/g·h). Notably, the photocatalytic H 2 production of 3%Co: CsPbBr 3 perovskite is significantly enhanced by applying an external magnetic field. Under the magnetic field of 2 T, the hydrogen production capacity of Co: CsPbBr 3 increased to 5300 μmol/g in 4 h, with the maximum hydrogen production rate of 1828.36 μmol/g·h in the first hour, being 3.14 times the maximum hydrogen production rate of CsPbBr 3 without magnetic field. The corresponding mechanism is systematically investigated by a vibrating-sample magnetometer, Electron paramagnetic resonance, UV–visible absorption, and photoluminescence spectra. The photocurrent and EIS were applied to investigate the charge-transfer kinetics of Co–CsPbBr 3. The excellent photocatalytic H 2 production efficiencies are because the doping of magnetic Co into highly polarized orthorhombic CsPbBr 3 increased the number of spin-polarized photo-generated carriers while applying magnetic field provided spin polarization and more electron transport channels, suppressing the recombination efficiency of electrons and holes. Manipulating spin-polarized electrons in highly polarized orthorhombic photocatalytic semiconductors provides an effective strategy to boost photocatalytic H 2 production efficiencies. [ABSTRACT FROM AUTHOR]

A novel donor–acceptor conjugated polymeric carbon nitride (D/A-CN) was synthesized by grafting benzene ring and pyridine moiety into the backbone of CN. D/A-CN delivers the superior photocatalytic performance benefitted from the synergy of the faster carrier transfer kinetics and the stronger reductive thermodynamics. [Display omitted] High-efficiency photocatalysts based on organic polymeric semiconductor are often limited by slow charge separation kinetics and sluggish redox reaction dynamics. Herein, the donor–acceptor conjugated polymeric carbon nitride (D/A-CN) was synthesized by grafting benzene ring and pyridine moiety into the backbone of CN through a flexible pyrolysis strategy. The D/A-CN shows a high photocatalytic H 2 evolution rate of 4795 µmol·h−1·g−1, which is ≈6.08 times higher than that of pristine CN (787.5 µmol·h−1·g−1). Both experimental and theoretical results confirm that the robust internal electric field is established in the D/A-CN framework due to the enhanced molecular dipole, which apply a kinetic force to facilitate the separation and mobility of photogenerated carriers. Meanwhile, the deeper conduction band potential caused by the elevated orbital energy level of D/A-CN contributes to the enhanced reduction ability of photoinduced electron. Consequently, the faster carrier transfer kinetics and the stronger thermodynamic reduction driving force synergistically lead to efficient photocatalytic H 2 production of D/A-CN. This work reinforces the comprehension of the structure-performance relationship of donor–acceptor structural photocatalysts and provides an insight for enhancing the photocatalytic activity of polymeric photocatalysts at the molecular level. [ABSTRACT FROM AUTHOR]

TiO 2 -based composites are promising photocatalysts for efficient generation of the clean energy, H 2 , from water splitting. Herein, series of Pd nanoparticles and carbon quantum dots (CQDs) co-decorated TiO 2 nanosheets (NSs), Pd-CQDs/TiO 2 , were designed by overall considering taking advantages of the three components: highly active TiO 2 NSs, highly conductive CQDs and electron sink of Pd. Series of photocatalytic experiments were performed and the photocatalytic reaction mechanism was explored. The Pd-0.5CQDs/TiO 2 exhibited an excellent photocatalytic hydrogen evolution rate (HER), which is 901.5, 41.8 and 1.7 times higher than those of the bare TiO 2 , 0.5CQDs/TiO 2 and Pd/TiO 2 , respectively. The synergistic effect of the CQDs and Pd was found responsible for the enhanced photocatalytic activity of the Pd-0.5CQDs/TiO 2. Besides, the CQDs was found facilitating complete conversion of Pd2+ to metallic Pd on the surface of TiO 2 NSs, which may offer a new thought for design of other composite materials. [Display omitted] • Pd and carbon quantum dots co-decorated TiO 2 nanosheets were designed and prepared. • Pd-0.5carbon quantum dots/TiO 2 exhibited high photocatalytic H 2 production activity. • Synergistic effect of Pd and carbon quantum dots is responsible for enhanced activity. • Carbon quantum dots facilitated conversion of Pd2+ to Pd0 on the TiO 2 nanosheets. • Photocatalytic reaction mechanism was explored based on experimental results. [ABSTRACT FROM AUTHOR]

Utilizing photocatalysts devoid of noble metals for solar hydrogen production is a viable option in resolving the rising energy crisis. However, the current photocatalytic performance is inadequate due to the insufficient conversion of solar energy into storable chemical energy. Photocatalysts with bulk-twinned homojunction for enhanced photocatalytic performance have received attention in recent years. In addition, it has been demonstrated that introducing sulfur vacancies is an effective approach to improving the photocatalytic performance of metal sulphides. A key factor in increasing photocatalyzed solar hydrogen production is the charge separation and limiting their recombination using stacking fault. Herein, we synthesized novel nanocrystal solid solutions of twinned wurtzite/zinc blende, Cd x Zn 1-x S (x = 0.1, 0.3, 0.5, 0.7 and 0.9), having rich sulfur vacancies. The solid solutions were prepared via a facile alkaline-assisted hydrothermal pathway, and then the activity, morphology, and surface properties were correlated using extensive characterization techniques. It was found that the Cd 0·5 Zn 0·5 S solid solution with twinned homojunction and rich sulfur vacancies exhibited a higher solar hydrogen production activity and stability than the bare Cd 0·5 Zn 0·5 S solid solution. [Display omitted] • Cd x Zn 1-x S solid solutions were synthesized via an alkaline-assisted hydrothermal pathway. • Twinned homojunctions boost the separation of photoexcited electrons and holes. • Sulfur vacancies serve as adsorption sites and traps for electron-hole recombination. • Optimized twinned crystals Cd 0·5 Zn 0·5 S with sulfur vacancies, had the highest H 2 production rate of 850 μmol (h. g cat)−1. [ABSTRACT FROM AUTHOR]

Metallic 1T phase MoS 2 with abundant edge and substrate active sites as cocatalysts were decorated on ZnIn 2 S 4 nanoflowers to construct 1T-MoS 2 @ZnIn 2 S 4 composites, which achieved an excellent H 2 production rate (15.6125 mmol g-1 h-1). [Display omitted] The formation of composites by loading co-catalysts on semiconductor photocatalysts to improve hydrogen (H 2) evolution performance is a feasible strategy. Metallic 1T phase molybdenum disulfide (MoS 2) as cocatalysts were decorated on zinc indium sulfide (ZnIn 2 S 4) nanoflowers by a grinding method to construct 1T-MoS 2 @ZnIn 2 S 4 composites. The H 2 production rate of 1T-MoS 2 @ZnIn 2 S 4 composites with optimum 7 wt% 1T-MoS 2 loading achieves 15.6 mmol g−1 h−1, 5.5 times higher than ZnIn 2 S 4 nanoflowers. The apparent quantum efficiency (AQY) increases from 3.1 % (ZnIn 2 S 4 nanoflowers) to 13.0 % (1T-MoS 2 @ZnIn 2 S 4 composites) under the wavelength light irradiation at λ = 370 nm. The loading of metallic 1T-MoS 2 with abundant edge and substrate active sites on ZnIn 2 S 4 can enhance visible light absorption, promote the transfer of electrons, and inhibit carrier recombination, thereby improving photocatalytic performance. This work offers inspiration for the design of composite photocatalysts with efficient photocatalytic capabilities. [ABSTRACT FROM AUTHOR]

Vanadium-carbide (V 2 C) MXenes have received scientific attention for their thinner structure, multiple oxidation states, and excellent conductivity, which can effectively serve as electron-sinking sites to suppress the backward recombination of electrons and holes. Herein, well-structured V 2 C/g-C 3 N 4 nanohybrids were designed to promote photocatalytic hydrogen production. Stronger interfacial contact between 2D/2D V 2 C/g-C 3 N 4 proffers 4.23-fold more H 2 yield than pristine g-C 3 N 4 with a maximal rate of 360 μmol g−1 h−1. The loading of V 2 C improves the light absorption capability and facilitates the charge transfer for photo-redox reaction. However, h+ accumulation fosters the degradation kinetics over consecutive cycles, which drives the homolytic cleavage of the g-C 3 N 4 by hydroxyl radical (• OH). The tremendous decline in the photostability test over methanol-containing sacrificial reagents is consistent with the reduction of g-C 3 N 4 functional units, corroborating the structural breaking. Employing TEOA as a hole scavenger slows the homolytic decomposition of g-C 3 N 4 , which could act as a binding ligand in protecting the g-C 3 N 4 surface. Stronger intermolecular forces between the heterogeneous molecules with excellent scavenging activity effectively trap accumulated h+ and slow down the degradation kinetics. The findings of this work not only contribute to the scientific understanding of vanadium-based MXenes in photocatalytic hydrogen production but also lay the foundation for understanding the mechanistic structure of g-C 3 N 4. [Display omitted] • Fabrication of V 2 C/g-C 3 N 4 with sheet-on-layer morphology for photocatalytic hydrogen production. • A large interface barrier formation in V 2 C/g-C 3 N 4 promotes photocatalytic hydrogen production. • 2D/2D V 2 C/g-C 3 N 4 proffers 4.23-fold photocatalytic enhancement than pristine g-C 3 N 4. • Gradual declination in photostability with methanol was due to the possible decomposition of g-C 3 N 4 through • OH attack. • A continuous and stable H 2 yield was obtained using TEOA due to the formation of the protective layer. [ABSTRACT FROM AUTHOR]

Developing efficient photocatalysts for H 2 production holds great promise to enhance solar energy conversion. In this study, we present a facile strategy to enhance H 2 production by simultaneously engineering Pt cocatalyst and oxygen vacancies (Vo) on mesoporous N doping TiO 2 , thereby developing efficient photocatalysts for solar energy conversion. Firstly, we employed a structure-directing agent-assisted approach to synthesize a series of mesoporous N doping TiO 2 spheres, inducing Vo. Among the samples, the ammonium hydroxide-assisted variant (A-TiO 2) exhibited the largest specific surface area of 52.9 m2 g−1 and Vo formation. Subsequently, the Vo-containing mesoporous N-TiO 2 spheres (A-TiO 2), when doped with 1 wt% Pt and employing methanol as a sacrificial agent, demonstrated remarkable performance. Under simulated sunlight irradiation, A-TiO 2 /Pt spheres exhibited an impressive hydrogen evolution rate of 14320.89 μmol g−1 h−1, surpassing the most of previously reported TiO 2 nanostructures. Experimental studies have elucidated the synergistic effect of Pt nanoparticles and Vo on TiO 2 in boosting the photocatalytic reaction. This offers a facile and scalable method for the synthesis of defective TiO 2 photocatalysts, thus facilitating mass production and promoting their potential commercialization. • A structure-directing agent-assisted method was used to fabricate mesoporous N doping TiO 2 spheres. • Oxygen vacancies were induced by N doping process. • Ammonium hydroxide-assisted sample (A-TiO 2) exhibited the largest S BET. • A-TiO 2 /Pt (1 wt%) achieved an rate of 14320.89 μmol g−1 h−1 under simulated sunlight irradiation. [ABSTRACT FROM AUTHOR]

Indium oxide (In 2 O 3) is a promising semiconductor used for various photocatalytic reactions, yet the green and template-free synthesizing the different micro/nanostructured In 2 O 3 with tunable morphology is still full of challenge. In this study, the three morphological In 2 O 3 with 3D micro-cubelike (In 2 O 3 -MC), 3D micro-ricelike (In 2 O 3 -MR), and 2D nano-platelike (In 2 O 3 -NP) were successfully fabricated through a facile hydrothermal strategy without any organic template additives. Owing to the enlarged specific surface area, promoted charge migration rate and suitable surface oxygen vacancies density, the unique 3D ricelike In 2 O 3 -MR exhibited the best photocatalytic H 2 generation activity from biomass glucose solution, which was 1.9-fold and 1.7-fold higher than that of In 2 O 3 -MC and In 2 O 3 -NP under the same experimental conditions. In addition, the optimum photoactivity of In 2 O 3 -MR was achieved under the alkaline environment with pH = 11 and 1.0 wt% Pt cocatalyst loading, which was better than the most of previously reported In 2 O 3 -based photocatalysts. Simultaneously, the possible photocatalytic mechanism for solar H 2 evolution from glucose solution was also discussed. Our work will bring about potential application in preparation of other photocatalysts with controlling morphology for renewable photocatalysis. [Display omitted] • The micro/nanostructured In 2 O 3 were prepared by a template-free hydrothermal strategy. • In 2 O 3 materials were firstly used for photocatalytic H 2 generation from biomass glucose solution. • The photoactivity of In 2 O 3 -MR was higher than most of the reported In 2 O 3 -based materials. • The micro/nanostructured In 2 O 3 can be applied for sustainable glucose-to-H 2 evolution. [ABSTRACT FROM AUTHOR]

The H 2 production from water-splitting and dehydrogenation of waste alcohols is widely investigated in current years to find out greener, and more efficient photocatalyst materials. Reduced graphene oxide (rGO; 1-10 wt%) coated TiO 2 and Ag(1 wt%)-TiO 2 core-shell nanocomposites are fabricated for enhanced photocatalytic H 2 production from H 2 O-splitting and CH 3 OH-dehydrogenation under UV irradiation. These rGO@TiO 2 and rGO@Ag–TiO 2 catalysts are characterized by XRD, Raman, FE-SEM, HR-TEM, XPS, BET, CV, EDS-mapping, PL, and UV–vis DRS for morphological, structural, and optical properties. After rGO(1-3 wt%) coating over TiO 2 , the H 2 amount is increased from 5 to 14 mmol for H 2 O-splitting and 13–83 mmol via CH 3 OH-dehydrogenation during 5 h UV irradiation, respectively. Due to the synergetic effect of rGO and Ag, core-shell rGO(2-4 wt%) coated Ag–TiO 2 produced the highest amount of 108–133 mmol of H 2 from water-splitting and 440–450 mmol from CH 3 OH-dehydrogenation during 7 and 5 h UV irradiation, respectively. The work illustrates the potential of Ag-deposition and rGO-coating over TiO 2 for efficient H 2 production. This paper reports the high photocatalytic activity of core-shell rGO@Ag–TiO 2 nanostructure for improved H 2 production (∼14 mmol/h) via water splitting and (∼90 mmol/h) via dehydrogenation of methanol under 5 h UV light irradiation. [Display omitted] • Core-shell nanostructure of rGO@TiO 2 and rGO@Ag–TiO 2 are fabricated. • rGO coating and Ag deposition highly improved the photocatalytic activity of TiO 2. • rGO@Ag–TiO 2 displayed superior photoactivity than rGO@TiO 2 nanocatalyst. • Highest amount of H 2 gas is photogenerated by rGO@Ag–TiO 2 photocatalysts. • Efficient H 2 O splitting and CH 3 OH dehydrogenation by rGO@Ag–TiO 2 composite. [ABSTRACT FROM AUTHOR]

Telluriums (Te) with various nanostructures, including particles, wires, and sheets, are controllably synthesized by adjusting the content of polyvinylpyrrolidone (PVP) in a facile solvothermal reaction. Te nanostructures all have complete grain sizes with excellent crystallinity and mesopore structures. Further, the formation mechanisms of Te nanostructures are proposed to be that the primary nuclei of Te are released from the reduction of TeO32− using N2H4·H2O, and then grow into various nanostructures depending on the different content of PVP. These nanostructures of Te all exhibit the photocatalytic activities for the degradation of MB and H2 production under visible light irradiation, especially Te nanosheets, which have the highest efficiencies of degradation (99.8%) and mineralization (65.5%) at 120 min. In addition, compared with pure Te nanosheets, the rate of H2 production increases from 412 to 795 μmol∙h−1∙g−1 after the introduction of Pt, which increases the output by nearly two times. The above investigations indicate that Te with various nanostructures is a potential photocatalyst in the field of degradation of organic pollutants and H2 fuel cells. [ABSTRACT FROM AUTHOR]

Due to their environmentally benign elemental components, suitable bandgap and high absorption coefficient in the visible-light range, Cu-based multinary sulfides exhibit excellent photocatalytic properties. Moreover, the adjustable atomic structure and unique electronic state of Cu-based multinary sulfide semiconductors can boost their ability to absorb visible light. In this review, we provide a summary of recent progress in photocatalytic applications of Cu-based multinary sulfide nanomaterials, including Cu-based ternary sulfides (CuInS2, CuIn5S8, Cu3SnS4, CuFeS2, etc.) and Cu-based quaternary sulfides (CuZnInS, Cu2ZnSnS4, CuZnGaS, CuInGaS, etc.). We start with a review of the bandgap alignments of Cu-based ternary sulfides and Cu-based quaternary sulfides, which are the key factors for the photocatalytic activity of semiconductor photocatalysts. Then, we discuss the advancements in photocatalytic applications of Cu-based multinary sulfide photocatalysts, including photocatalytic H2 production, CO2 reduction, organic synthesis and degradation of pollutants and photoelectrochemical H2 production. Finally, we end this review with a summary of the current challenges and opportunities of Cu-based multinary sulfides in future studies.

In this study, we fabricated graphitic carbon nitride (g-C3N4) nanosheets with embedded ZnCdS nanoparticles to form a type II heterojunction using a facile synthesis approach, and we used them for photocatalytic H2 production. The morphologies, chemical structure, and optical properties of the obtained g-C3N4–ZnCdS samples were characterized by a battery of techniques, such as TEM, XRD, XPS, and UV-Vis DRS. The as-synthesized g-C3N4–ZnCdS photocatalyst exhibited the highest hydrogen production rate of 108.9 μmol·g−1·h−1 compared to the individual components (g-C3N4: 13.5 μmol·g−1·h−1, ZnCdS: 45.3 μmol·g−1·h−1). The improvement of its photocatalytic activity can mainly be attributed to the heterojunction formation and resulting synergistic effect, which provided more channels for charge carrier migration and reduced the recombination of photogenerated electrons and holes. Meanwhile, the g-C3N4–ZnCdS heterojunction catalyst also showed a higher stability over a number of repeated cycles. Our work provides insight into using g-C3N4 and metal sulfide in combination so as to develop low-cost, efficient, visible-light-active hydrogen production photocatalysts. [ABSTRACT FROM AUTHOR]

In this study, Ag/ZnO photocatalyst is synthesized in ethylene glycol (EG) medium using a one-pot hydrothermal method, where EG serves as both a reaction medium for the synthesis and a reduction medium for silver. Standard analytical techniques such as XRD, XPS, SEM-EDX, TEM, HR-TEM FTIR, BET, and UV–Vis spectroscopy are used to characterize the synthesized samples. The XRD and HR-TEM results show that Ag has been decorated on the ZnO photocatalyst. The results show that spherical Ag/ZnO has the highest photocatalytic activity for H 2 evolution (30.1 μmol h−1) and RhB degradation. The increased photocatalytic activity can be attributed to the formation of the Schottky barrier at the heterojunction interface of metal-semiconductor and the plasmonic resonance effect of silver, which results in efficient separation and transportation of photo-induced charge carriers. This research could open up new avenues for the development of advanced ZnO-based visible light photocatalytic materials to address energy and environmental challenges. [Display omitted] • Simple hydrothermal method was used to design a multifunctional Ag/ZnO photocatalyst. • Ag/ZnO photocatalyst with spherical shape exhibited the highest H 2 evolution and RhB degradation with excellent photostability. • H 2 evolution for Ag/ZnO is 123 times higher than pristine ZnO, reaching 30 μl/h. • H 2 evolution is accelerated by Schottky barriers and LSPR-induced electrons from Ag under light illumination. [ABSTRACT FROM AUTHOR]

The photocatalytic production of hydrogen has been reported as an attractive strategy given the possibility of using renewable sources such as sunlight and biomass. The scalability of the process involves optimizing the design of the reaction system, minimizing the cost and time spent on the stages of separation, purification and reuse of the catalyst. This work demonstrates the application of photocatalytic plates impregnated with TiO 2 doped with small doses of platinum (Pt) in the photoreforming of glycerol under visible radiation. The optimized amount of catalyst was 25 mg, corresponding to an average hydrogen production rate in 3 h of reaction of 316 mmol H 2.h−1.m−2, this value being independent of the platinum concentration range tested (0.1%–1.0%, w/w). The kinetic behavior of the photocatalytic plates was similar to the application of the catalyst in powder form. The presence of 0.3% platinum in the catalyst composition led to the maintenance of photocatalytic stability for 7 consecutive application cycles, indicating operational viability without appreciable loss of performance, brings good prospects for expanding the scale of the process and allowing the development of continuous flow operations. • Proposition of photocatalytic plates for hydrogen generation. • High performance at low platinum dosages. • Kinetic performance of the plates equivalent to the powdered material. • Maintenance of photocatalytic stability in consecutive cycles. • Perspective of expanding the scale of photocatalytic production of H 2. [ABSTRACT FROM AUTHOR]

The photocatalytic reduction of CO2 into solar fuel is considered a promising approach to solving the energy crisis and mitigating the environmental pollution caused by anthropogenic CO2 emission. Some powder photocatalysts have been demonstrated as efficient, but their drifting properties, along with difficult separation (catalyst and product), make continuous mode reaction very challenging, particularly in the liquid phase. In order to make this process commercially viable and economically more efficient, we have developed a simple and scalable method for immobilizing TiO2 P25 over the surface of glass slides using an organic-based surfactant. Improved adhesion properties and the homogeneous dispersion of catalyst nanoparticles were achieved. A holder was designed with 3D printing technology in such a way that it can hold up to six slides that can be dipped simultaneously into the suspension or solution of desired materials for a uniform and homogeneous deposition. The resulting surfaces of the dip-coated materials (e.g., TiO2 P25) were further modified by adding metallic nanoparticles and thoroughly characterized via XRD, DRS UV–Vis, SEM, and SEM–EDX. Photocatalytic tests have been performed for two major applications, viz., hydrogen production via the photoreforming of glucose and the photoreduction of CO2 into different solar fuels. The latter tests were performed in a specially designed, high-pressure reactor with Ag/P25 supported catalysts, which exhibited about three times higher formic acid productivity (ca. 20 mol/kgcat h) compared to the dispersed catalyst, with enhanced stability and recoverability. It is to note that catalysts deposited on the glass slides can easily be recovered and the materials did not show any weight loss. To the best of our knowledge, the obtained formic acid productivity is highest among the published literature. [ABSTRACT FROM AUTHOR]

The advantage of a complex catalyst in which several catalysts are mixed is that the overall reaction rate can be efficiently increased by increasing each sub-reaction rate. Each constituent catalyst in the complex catalyst must be as well-mixed as possible—while maintaining high catalytic activity—owing to the short reaction time of these sub-reactions. This study reports a facile synthetic method to mix two catalysts homogeneously at the nanoscale while keeping their crystal structure intact. ZnNiCu hydroxide nanoplates with a mixed crystal structure composed of ZnNi and ZnCu hydroxides, which could promote H 2 O dissociative adsorption and H 2 desorption, respectively, were synthesized by a simple cation exchange of ZnO nanoparticles and a precursor mixture of Ni and Cu. ZnNi and ZnCu hydroxides in the nanoplates were mixed at the nanoscale while maintaining their respective crystal structures; density functional theory calculations show that these structures could effectively perform H 2 O dissociative adsorption and H 2 desorption, respectively, resulting in high activity in the overall photocatalytic hydrogen evolution reaction. ZnNiCu hydroxide composites were prepared, and photocatalyst H 2 productivity was predicted through DFT calculations. The well-mixed structure of ZnNi and ZnCu hydroxides at the nanoscale with keeping their crystal structures plays key role in maintaining fast reaction rates of both H 2 O dissociative adsorption (ZnNi hydroxide) and H 2 desorption (ZnCu hydroxide). [Display omitted] • Synthesis of ZiNiCu hydroxide (ZNC) nanoplates by cation exchange. • Enhanced photocatalytic H 2 production caused by ZnNi/ZnCu mixture hydroxide structure. • Investigation of enhanced H 2 production through experiment and DFT calculation. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) materials featured large specific surface area, unique porous structure and highly crystalline nature which rendered them ideal catalysts in solar light conversion. Generally, the catalytic H 2 generation activity of the MOFs was rather low which restricted its application. The effective co-catalyst introduction could enhance its overall performance via reducing the overpotential of hydrogen production while facilitating charges transfer and increasing reactive sites. Herein, an two-dimensional (2D) O,P–MoS 2 nanosheets cocatalyst with adequate edge-S active sites and high 1T-phase content were fabricated via co-doping of O and P atoms. Rational coupling the 2D O, P–MoS 2 nanosheets with 2D NH 2 -MIL-125(Ti) nanoplate can afford greatly improved photocatalytic H 2 production rate of 339.3 μmol⋅g−1⋅h−1, which was 11.6 and 6.7 times of pure NH 2 -MIL-125(Ti) and NH 2 -MIL-125(Ti)/commercial MoS 2 composite, respectively. DFT calculation revealed that the edge-S serve as the active sites for H∗ adsorption rather than the plane-S and O sites in O, P–MoS 2 or the O and S sites in O–MoS 2. Compared with the commercial MoS 2 with completely 2H-phase, the dual-doping can create higher-density unsaturated edge-S atoms and more 1T phase which can improve the reactivity of NH 2 -MIL-125(Ti) via inducing the breaking of Mo–S bonds and providing higher electrical conductivity. Dual non-metal atom doping of MoS 2 cocatalyst featured abundant edge-S active centers and high concentration of 1T-phase offered a facile and effective method to developing highly efficient catalysts toward solar-energy conversion. • O, P–MoS 2 nanosheet cocatalyst with abundant edge-S active sites and high 1T-phase content was prepared. • 2D/2D O,P–MoS 2 /NH 2 -MIL-125(Ti) composite greatly enhanced the photocatalytic HER efficiency. • The increased edge-S sites and enhanced metallic property of O,P–MoS 2 /NH 2 -MIL-125(Ti) composite boosted charge separation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Glucose conversion assisted photocatalytic water splitting technology avoid the use of sacrificial agents while realizing co-product of H 2 and high value-added chemicals. • Both hierarchical 3DOM structure and type Ⅱ heterojunction are conducive to the absorption and utilization of light and the separation and transmission of carriers. • The 3DOM CTO-ZCS photocatalyst simultaneously has high photocatalytic H 2 production performance (2.81 mmol g-1h−1) and high glucose conversion (85.57 %). • The conversion of glucose to lactic acid is a two-step reaction and the control reaction step is gluconic acid to lactic acid. Glucose conversion assisted photocatalytic water splitting technology to simultaneously produce H 2 and high value-added chemicals is a promising method for alleviating the energy shortage and environmental crisis. In this work, we constructing type II heterojunction by in-situ coupling Zn 0.3 Cd 0.7 S quantum dots (ZCS QDs) on three-dimensionally ordered microporous CaTiO 3 (3DOM CTO) for photocatalytic H 2 production and glucose conversion. The DFT calculations demonstrate that substitution of Zn on the Cd site improves the separation and transmission of photogenerated carriers. Therefore, 3DOM CTO-ZCS composite exhibits best H 2 production performance (2.81 mmol g-1h−1) and highest apparent quantum efficiency (AQY) (5.56 %) at 365 nm, which are about 47 and 18 times that of CTO nanoparticles (NPs). The improved catalytic performance ascribed to not only good mass diffusion and exchange, highly efficient light harvesting of 3DOM structure, but also the efficient charges separation of type Ⅱ heterojunction. The investigation on photocatalytic mechanism indicates that the glucose is mainly converted to gluconic acid and lactic acid, and the control reaction step is gluconic acid to lactic acid. The selectivity for gluconic acid on 3DOM CTO-ZCS is 85.65 %. Our work here proposes a green sustainable method to achieve highly efficient H 2 production and selective conversion of glucose to gluconic acid. [ABSTRACT FROM AUTHOR]