Photocatalytic Hydrogen Production Research Articles

Facile Fabrication of SrTiO3/In2O3 on Carbon Fibers via a Self-Assembly Strategy for Enhanced Photocatalytic Hydrogen Production

Photocatalytic water splitting by semiconductors is considered a promising and cost-effective method for achieving sustainable hydrogen production. In this study, a CF/SrTiO3/In2O3 photocatalytic material with a double-layer core–shell structure was developed. The experimental results indicated that the produced CF/SrTiO3/In2O3 composite fiber displayed superior photocatalytic hydrogen production performance, achieving a hydrogen evolution rate of approximately 320.71 μmol/g·h, which is roughly seven times higher than that of the CF/SrTiO3 fiber alone. The enhanced photocatalytic activity of the CF/SrTiO3/In2O3 fiber can be attributed to the heterojunction structure enriched with oxygen vacancies. It was found that these oxygen vacancies created defective states that served as traps for photogenerated electrons, facilitating their migration to the surface defect states and enabling the reduction of H+ in water to produce hydrogen. Furthermore, the synergy between the heterojunction structure and the conductivity of the carbon fiber promoted the generation and migration of photogenerated electrons, reduced the recombination of photogenerated electron–hole pairs, and ultimately improved photocatalytic hydrogen production. This study presents a new approach for designing efficient photocatalysts with surface oxygen vacancies on carbon fibers, providing new insights into the sustainable application of photocatalysts.

Preparation and Photocatalytic Hydrogen Evolution Performance Study of NENU‐5/CuBr/Graphdiyne Tandem S‐Scheme Heterojunction

Graphdiyne (GDY) has been widely applied in the field of photocatalytic hydrogen production due to its unique chemical structure and excellent photoelectric performance. Herein, CuBr is used as a catalytic substrate to prepare CuBr/GDY through a cross‐coupling reaction, and a novel NENU‐5/CuBr/GDY tandem S‐scheme heterojunction photocatalyst is constructed at low temperature. The NENU‐5/CuBr/GDY heterojunction exhibits significantly enhanced activity in photocatalytic hydrogen evolution, with hydrogen evolution reaching 226.62 μmol in 5 h, which is 4.7 and 12.6 times greater than that of pure GDY and NENU‐5, respectively. Comprehensive evaluation of electrochemical, photoluminescence, and time‐resolved photoluminescence indicates that the enhanced activity of the NENU‐5/CuBr/GDY composite catalyst is attributed to high photocurrent response and low electrical resistance, which increases the efficiency of photogenerated charge separation. Additionally, density functional theory calculations and ultraviolet photoelectron spectroscopy propose the possibility of constructing the NENU‐5/CuBr/GDY tandem S‐scheme heterojunction structure. In summary, this work provides valuable ideas into tandem heterojunctions for photocatalytic hydrogen production.

Boosting photocatalytic activity in ternary lamellar hierarchical structured ZnFe2O4/polymeric carbon nitride by constructing an electronic bridge

Photocatalytic technology is one of the ideal approaches for clean energy production and environmental pollution control in the future. However, the rapid recombination of photo-generated charge carriers is a bottleneck problem of low solar energy conversion efficiency. Herein, a magnetic ZnFe2O4/Pt/polymeric carbon nitride (PCN) semiconductor catalyst is designed and prepared for high-performance photocatalytic hydrogen production reaction and photocatalytic degradation rate of RhB. It exhibits 339.31 μmol·g−1·h−1 hydrogen production rate and 96.08 % photocatalytic degradation rate of RhB within 120 min under visible light. The introduction of Pt, constructing an electronic bridge, accelerated the transfer of photo-generated carriers, meanwhile, the smaller band gap of the ternary composites enabled the generation of more photo-generated electrons. The internal electric field accelerated the accumulation of electrons and holes in the conduction band of ZnFe2O4 and valence band of PCN, thus photocatalytic activity is greatly enhanced. The electron-hole separation is also improved and the transport of photo-generated electrons is facilitated by the special structure of the heterojunction and the unique morphology of PCN. In addition, the used catalyst can be recovered through magnetic fields, and this magnetic catalytic system has great application prospects in the fields of photocatalytic hydrogen production and pollutant degradation.

P-doped ultrathin g-C3N4/In2S3 S-scheme heterojunction enhances photocatalytic hydrogen production and degradation of ofloxacin

In this work, ultrathin lamellar g-C3N4/In2S3 S-scheme heterojunctions doped with P were synthesized by urea recrystallization and investigated to see which ratio was more favorable for photocatalysis. The P doping formed a new Fermi energy level and reduced the forbidden bandwidth. The ultrathin lamellar structure facilitated rapid charge transfer, and the formation of S-scheme heterojunction, the presence of the interfacial electric field, and band bending effectively separated strong redox-capable electron-hole pairs, thus significantly improving the photocatalytic performance. Among the prepared materials, the 50UP-C3N4/In2S3 photocatalyst with 50 % UP-C3N4 mass fraction showed optimal photocatalytic H2 production performance, with a hydrogen production rate of 12,387 μmol h−1 g−1. Moreover, it showed good performance in photocatalytic degradation, with a degradation efficiency of up to 90.2 % of ofloxacin after 120 min of light exposure. This article provided a new perspective on the synthesis of other photocatalysts with carbazide-based S-scheme heterojunction structures.

The enhancement of photocatalytic hydrogen production over Ag2WO4 modified g-C3N4 with Pt as cocatalyst

ABSTRACT The construction of heterojunction photocatalyst is an effective mean to improve the photoexcited electron–hole pair separation. The Ag2WO4-doped graphitic carbon nitride (g-C3N4, C3N4 for short) composite photocatalysts were fabricated by a simple calcination and in-situ depositing strategy. The composites were characterized by different techniques. The effects of Ag2WO4 content, type of scavengers, pH value of reaction solution and dose of scavenger on photocatalytic hydrogen (H2) generation were studied. It was found that the Ag2WO4 micro-nano particles were highly dispersed on the C3N4 surface. After doping Ag2WO4, the light absorption range of Ag2WO4-C3N4 material was broadened effectively from 440 nm to 448 nm, and the BET surface area of C3N4 was increased from 35.63 to 40.73 cm2·g−1, indicating that Ag2WO4 loading could provide some new BET surface areas. The binding energy of all elements in Ag2WO4-4/C3N4 was clearly shifted due to the charge transfer from C3N4 to Ag2WO4, implying a strong interaction between C3N4 and Ag2WO4. The photocatalytic H2 production rate of the optimized Ag2WO4-4/C3N4 was 6047.4 μmol·g−1·h−1, which was 2.04 and 171.8 times that of C3N4 and Ag2WO4, respectively. While Ag2WO4-4/C3N4 exhibited a poor H2 production performance in the absence of Pt co-catalyst (309.3 μmol·g−1·h−1), indicating the formation of heterojunction among Ag2WO4, C3N4 and Pt.

Efficient visible light photocatalytic green hydrogen production from Dy2O3 combined with nitrogen-deficient g-C3N4

The efficient construction of heterojunction photocatalysts has a crucial significance in achieving the decomposition of water for hydrogen generation. This work successfully prepared nitrogen-deficient g-C3N4 (ND-g-C3N4) and combined it with dysprosium oxide (Dy2O3) through high-temperature calcination to create a type II heterojunction photocatalyst (Dy2O3/ND-g-C3N4). Notably, under visible light, the Dy2O3/ND-g-C3N4 photocatalyst demonstrated impressive hydrogen production rates in both ethylene glycol and glucose solutions. Specifically, the photocatalyst achieved H2 generation rates of 463.256 and 510.305 μmol∙g-1∙h-1 in ethylene glycol and glucose solutions, respectively. And the quantum yield could be up to 21.76% and 23.96%, respectively. Furthermore, the photocatalytic reforming of glucose for H2 production yielded valuable intermediate products. The inclusion of an f-shell layer in the Dy2O3 lattice has a significant function in enhancing photocatalytic hydrogen production efficiency. This improvement was attributed to the ability of the f-shell layer to capture excited electrons, thereby decreasing the rate of recombination of exciton pairs.

Erythrocyte-like ACET Anchored on Graphitic Carbon Nitride with Activating π-Conjugated Electron Transfer for Enhanced Photocatalytic Hydrogen Production

Activating π-conjugated electron transfer in graphitic carbon nitride (g-C3N4), not only enhances the absorption of solar light, but also broken through energy barrier, sequentially leading to increased photocatalytic hydrogen production. However, g-C3N4 itself is prone to agglomeration, wide bandgap, weak absorption of visible light, poor electrical conductivity and so on, which seriously restrict its photocatalytic performance, therefore activating π-conjugated electron transfer is confronted with great challenges. Herein, we show that activating π-conjugated electron transfer by breaking tri-s-triazine unit of g-C3N4 through a simple one-step gas template method. As a result, the best performed CN-4 sample exhibit an outstanding hydrogen production rate of 1282 μmol h-1 g-1, which is 455% higher than that of the pristine g-C3N4 (282 μmol h-1 g-1). Moreover, the density functional theory (DFT) calculations suggest that the original π-conjugated electrons equilibrium system has been a significant transformation by C-doping. The results present a new direction of thought that utilizes π-conjugated electrons transfer to enhance the photocatalytic hydrogen generation by breaking tri-s-triazine unit.

BiOCl modified TiO2 based catalyst with enhanced hydrogen generation properties under visible light via promote photogenerated electron-hole separation

Due to its wide band gap and low photogenerated carrier separation efficiency, TiO2 has an undesirable photocatalytic activity. In the present work, BiOCl was hydrothermally deposited on TiO2 and BiOCl/TiO2 composites with different ratios were obtained. The results show that 30 % BiOCl/TiO2 has the best performance of 1354.94 μmolg−1h−1, which is 18.4 times than pure TiO2 and 73.1 times than pure BiOCl. The significant increase in the photocatalytic efficiency of BiOCl/TiO2 composites is attributed to the reduction of their bandgap width and the fast separation of photogenerated electron-hole pairs. This work brings a new idea to increase the photocatalytic hydrogen production capability of TiO2.

Boosting intimate contact and charge transfer between Carotenoid dye and Ti3C2Tx MXene for photocatalytic hydrogen production

Boosting intimate contact and charge transfer between Carotenoid dye and Ti3C2Tx MXene for photocatalytic hydrogen production

Enhancing catalytic activity of TiO2 nanoparticles through acid treatment in Eosin-Y sensitized photohydrogen evolution reaction system

Light-driven water splitting has gained increasing attention as an eco-friendly method for hydrogen production. There is a pressing need to enhance the performance of catalysts for the commercial viability of this reaction. Many methods have been proposed to improve catalyst performance; however, an economical and straightforward approach remains a priority. This paper presents an uncomplicated technique called acid treatment, which augments the catalytic performance of nanoparticles. The method promotes a change in the catalytic reactivity by causing a deficit in electron density of Ti and O on the surface of TiO2 nanoparticles without altering their size, morphology, or crystal structure. In the Eosin Y sensitized photocatalytic hydrogen production system, nitric acid treated TiO2 (16.95 μmol/g) exhibited 1.5 times the hydrogen production compared to bare TiO2 (11.15 μmol/g).

Efficient photocatalytic hydrogen production of Ni-Co layered double hydroxides (Ni-Co LDHs) anchored with reduced graphene oxide (rGO) hybrid composite

Using a suitable co-catalyst to boost photocatalytic H2 evolution from water splitting is crucial. Herein, we designed pristine NiCo-LDH and reduced graphene-oxide supported nickel-cobalt layered double hydroxide nanosheets (NiCo-LDH/rGO) as photocatalyst for the first time to evaluate the hydrogen production performance. Adding graphene has the potential to significantly increase electrical conductivity, and the supported NiCo-LDH has the potential to significantly reduce the likelihood of graphene self-aggregation. The effectiveness of its photocatalytic hydrogen generation was analyzed using a set of characterizations. The H2 evolution rates for pure rGO were 345.2 μmolh-1g-1, whereas those for Ni-Co LDH/rGO were 578.2 μmolh-1g-1. Average hydrogen generation per hour for the Ni-Co LDH/rGO composite material was 2032.1 μmolh-1g-1, which was 5.8 and 3.5 times that of rGO and Ni-Co LDH/rGO, respectively, NiCo-LDH@rGO's synergistic impact on the NiCo-LDH boosts the H2 generation pathway by increasing the catalyst's stability as well as performance by exposing active sites and speeding up electron transport. The produced nanocomposite shows excellent spatial charge separation and quicker electron transport across the conductive network of rGO, as shown by the photocurrent response test and photoluminescence (PL) spectra. The results of this study provide a fresh perspective on the practical use and synthesis of the inexpensive and effective NiCo-LDH/rGO, demonstrating the standard deviation of logical planning and preparation of high-performance photocatalysts.

Effect of precursors on Cu particle distribution in g-C3N4 nanosheets towards efficient photocatalytic degradation and H2 generation

N-rich precursors govern the thermal polymerization formation of graphitic carbon nitride (g-C3N4) based catalysts towards enhanced photocatalytic performance. In this paper, Cu components were introduced in superior thin g-C3N4 nanosheets using the thermal polymerization copper acetate and bulk g-C3N4 created by different precursors including melamine, dicyandiamide, and thiourea, such as melamine-g-C3N4 (MCN), dicyandiamide-g-C3N4 (DCN), and thiourea-g-C3N4 (TCN). The performance of Cu-g-C3N4 nanosheets depended strongly on the precursors of bulk g-C3N4 samples. The well-developed Cu nanoparticles with clear lattice fringes were observed in the sample prepared using MCN (sample Cu-MCN) while the crystallinity of Cu nanoparticles became worse in the sample prepared using DCN (sample Cu-DCN). Interestingly, Cu clusters were homogeneously distributed in superior thin g-C3N4 nanosheets in the case of using TCN (sample Cu-TCN) because of S components in thiourea affected the thermal polymerization. The photocatalytic activity of Cu-TCN was drastically improved compared with other Cu-g-C3N4 samples. The photocatalytic hydrogen production rate of Cu-TCN with 1% of Cu components was 4035.6 μmol g-1 h-1. Cycle stability test indicated that sample Cu-TCN revealed high stability, in which the H2 generation rate was retained 95% of their initial value after 5 cycles. These results supply efficient approaches for the study and application of g-C3N4 based photocatalysts.

2D MoB MBene: An Efficient Co-Catalyst for Photocatalytic Hydrogen Production under Visible Light.

Highly active and low-cost co-catalysts have a positive effect on the enhancement of solar H2 production. Here, we employ two-dimensional (2D) MBene as a noble-metal-free co-catalyst to boost semiconductor for photocatalytic H2 production. MoB MBene is a 2D nanoboride, which is directly made from MoAlB by a facile hydrothermal etching and manual scraping off process. The as-synthesized MoB MBene with purity >95 wt % is treated by ultrasonic cell pulverization to obtain ultrathin 2D MoB MBene nanosheets (∼0.61 nm) and integrated with CdS via an electrostatic interaction strategy. The CdS/MoB composites exhibit an ultrahigh photocatalytic H2 production activity of 16,892 μmol g-1 h-1 under visible light, surpassing that of pure CdS by an exciting factor of ≈1135%. Theoretical calculations and various measurements account for the high performance in terms of Gibbs free energy, work functions, and photoelectrochemical properties. This work discovers the huge potential of these promising 2D MBene family materials as high-efficiency and low-cost co-catalysts for photocatalytic H2 production.

Bismuth-Doped Carbon Dots Decorated Escherichia coli for Enhanced Hydrogen Production.

Photosynthetic inorganic biohybrid systems (PBSs) combining an inorganic photosensitizer with intact living cells provide an innovative view for solar hydrogen production. However, typical whole-cell biohybrid systems often suffer from sluggish electron transfer kinetics during transmembrane diffusion, which severely limits the efficiency of solar hydrogen production. Here, a unique biohybrid system with a quantum yield of 8.42% was constructed by feeding bismuth-doped carbon dots (Bi@CDS) to Escherichia coli (E.coli). In this biohybrid system, Bi@CDS can enter the cells and transfer the electrons upon light irradiation, greatly reducing the energy loss and shortening the distance of electron transfer. More importantly, the photocatalytic hydrogen production of the E.coli-Bi@CDs biohybrid system reached up to 0.95 mmol within 3 h under light irradiation (420-780 nm, 2000 W m-2), which is 1.36 and 2.38 times higher than that in the E.coli-CDs biohybrid system and the E.coli system, respectively. In addition, the mechanism of enhanced hydrogen production was further explored. It was found that the accelerated decomposition of glucose, the accelerated production of pyruvate, the inhibition of lactic acid, and the increase of formic acid were the reasons for the increase of hydrogen production. This work provides a novel strategy for improving the hydrogen production in photosynthetic inorganic biohybrid systems.

Novel Graphitic Carbon Nitride/Co-B-P Nanocomposites with Significantly Enhance Visible-Light Photocatalytic Hydrogen Production from Water Splitting

As a promising metal-free photocatalyst for hydrogen (H2) production through water splitting under visible-light irradiation, graphitic carbon nitride (g-C3N4) photocatalysts decorated with CoBP was prepared via simple ultra sonification. This paper highlights the structures of the photocatalysts, their stability, rate of hydrogen evolution and the mechanism of charge transfer within the photocatalysts. The prepared C3N4/CoBP nanocomposite photocatalysts were characterized by using X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, scanning electron microscopy and UV–visible (UV–vis) diffuse reflectance spectroscopy. After detailed analysis, the C3N4/CoBP nanocomposite photocatalysts showed excellent photocatalytic performance, which was due to the formation of the heterostructured hybrids of g-C3N4 and CoBP. The effects of C3N4/CoBP nanohybrids on H2 evolution were evaluated. The effects improved with increasing load of CoBP until the optimal level (5 wt% CoBP with visible-light irradiation at λ ≥420 nm). The maximum and remarkable photocatalytic H2 evolution rate of 51.68 μmol h−1 was achieved, which was 3.8 times that obtained from pure g-C3N4. Moreover, the C3N4/CoBP heterostructured nanohybrids demonstrated extremely high photostability and recyclability for H2 evolution after visible light illumination. The composite hybrid accelerated the separation and transfer of photogenerated charge carriers and subsequently suppressed charge recombination. Conclusively, this study offered an opportunity for the design and synthesis of highly stable and efficient C3N4/CoBP nanocomposite photocatalysts for energy conversion and utilisation.

Fabrication of CZS NRs/NiSx NPs hybrids with abundant S-vacancies for signally promoting photocatalytic hydrogen production

The cocatalysts play a key role in photocatalytic technology in remarkably improving the efficiency of H2 evolution. Herein, S vacancies-rich Cd0.6Zn0.4S nanorods (CZS NRs) were prepared via solvothermal method. Then, as-obtained CZS NRs were modified with Ni–Co PBA-derived NiSx nanoparticles (NPs) cocatalyst using grinding method. The optimized CZS/NiSx-N-1.5 hybrids (CZS/NiSx-N, where N represents nickel nitrate which was used as nickel source) exhibited outstanding stability and activity, the average rate of H2 was up to 192.82 mmolg−1h−1 in deionized water medium, which was 201.4% higher than that of CZS. Besides, NiSx-A and NiSx-C cocatalysts with different particle sizes were obtained using nickel acetate (A) and nickel chloride (C) as nickel source, respectively. The CZS/NiSx-C-1.5 and CZS/NiSx-A-1.5 exhibited the H2 evolution rate of 180.70 and 201.93 mmolg−1h−1 in deionized water medium, respectively. The as-prepared materials also exhibited the excellent H2 evolution performance in natural seawater medium. Besides, the photocatalytic mechanism of H2 evolution over CZS NRs/NiSs NPs was also discussed. This work develops a novel H2 evolution cocatalyst and unveils the relationship between the loading amount/particle size of cocatalyst on the H2 evolution rate.

Interfacial engineering between carbon vacancies modified graphitic carbon nitride and CoAl-LDH formed heterojunctions for improved photocatalytic performance: Degradation pathway, DFT calculations, and mechanism insights

The construction of green, low-cost heterojunctions with interfacial interaction is crucial to enhance their photocatalytic performance and broaden their utility in practical applications. Here, we prepared CoAl-LDH/Carbon Nitride with carbon vacancies (Cv-CN) heterojunction by electrostatic self-assembly strategy to explore its photocatalytic properties. 30 wt% CoAl-LDH/70 wt% Cv-CN (CCN-2) exhibited the optimal photocatalytic degradation performance after 120 min of light exposure, with a degradation efficiency of 93.1 %. Fukui function calculations, in conjunction with LC-MS/MS analysis, were employed to explore potential degradation pathways during the photocatalytic degradation of tetracycline. The photocatalytic performance of CoAl-LDH/Cv-CN heterojunction was further analyzed by photocatalytic hydrogen production experiments, and after five hours, the hydrogen production rate of CCN-2 was 2515 µmol/g (Cv-CN: 1554 µmol/g, CoAl-LDH: hardly produced any hydrogen). According to the experimental results and data analysis, an effective charge-carrier separation and transfer pathway is established through the interfacial engineering between CoAl-LDH and Cv-CN forming the heterojunction at the interface of CoAl-LDH and Cv-CN. The heterojunction structure formed by interfacial engineering between CoAl-LDH and Cv-CN enables effective photocatalytic removal of antibiotics and hydrogen production providing new insights into the treatment of aqueous environments and clean energy production.

Direct Z‐Scheme Heterostructure of Nanoparticle‐CdSe on Nanorod‐NaNbO3: Facile Hydro‐thermal Construction and Superior Photocatalytic Activity and Stability in H2 Evolution

The advancement of exceptionally effective catalysts that are photostable is significantly important for the sustainable conversion of solar energy into hydrogen. Combining the strengths of NaNbO3 and CdSe in a fabricated heterojunction has been pursued in photocatalysis to enhance the performance while addressing CdSe's stability. In this study, nanoparticle‐CdSe was deposited on NaNbO3 nanorods via hydrothermal method, and the optimal composite ratio of CdSe/NaNbO3 heterojunction achieved a photocatalytic hydrogen production of 2510 μmol g‐1h‐1. The enhancement is ascribed to the formation of a Z‐scheme heterojunction by the interface contact between CdSe and NaNbO3.The migration of electrons from NaNbO3 to CdSe was revealed by charge density difference results in DFT calculation. Work function of samples demonstrated the equilibrium of Fermi level and a corresponding shift of the band structure in the heterojunction. The H2 adsorption free energy (ΔGH*) for the heterojunction was 0.26 eV, suggesting a reduced energy barrier for hydrogen generation. Notably, the stable structure of NaNbO3 endows the composites with excellent chemical stability, maintaining more than 80% activity after six hydrogen production cyclic tests. This work offers valuable insights into the development of direct Z‐scheme structure catalysts for photocatalytic water splitting.

Structurally disordered MoSe2 with rich 1T phase as a universal platform for enhanced photocatalytic hydrogen production

The improvement of surface reactivity in noble-metal-free cocatalysts is crucial for the development of efficient and cost-effective photocatalytic systems. However, the influence of crystallinity on catalytic efficacy has received limited attention. Herein, we report the utilization of structurally disordered MoSe2 with abundant 1T phase as a versatile cocatalyst for photocatalytic hydrogen evolution. Using MoSe2/carbon nitride (CN) hybrids as a case study, it is demonstrated that amorphous MoSe2 significantly enhances the hydrogen evolution rate of CN, achieving up to 11.37 μmol h−1, surpassing both low crystallinity (8.24 μmol h−1) and high crystallinity MoSe2 (3.86 μmol h−1). Experimental analysis indicates that the disordered structure of amorphous MoSe2, characterized by coordination-unsaturated surface sites and a rich 1T phase with abundant active sites at the basal plane, predominantly facilitates the conversion of surface-bound protons to hydrogen. Conversely, the heightened charge transfer capacity of the highly crystalline counterpart plays a minor role in enhancing practical catalytic performance. This approach is applicable for enhancing the photocatalytic hydrogen evolution performance of various semiconducting photocatalysts, including CdS, TiO2, and ZnIn2S4, thereby offering novel insights into the advancement of high-performance non-precious catalysts through phase engineering.

Self-doped zinc-mediated ZnIn2S4 microflowers towards optimized visible-light photocatalytic hydrogen production

Doping is a favorable strategy for modifying the performance of ZnIn2S4 (ZIS). However, the doped heteroatoms are prone to be the sites of carrier complexation. According to the coordination structure and the bond order relationship in hexagonal ZIS, we synthesized Zn self-doped ZIS as an efficient hydrogen evolution reaction (HER) photocatalyst by one-step hydrothermal method. By adjusting the content of Zn in the reaction precursor, the excess Zn competes with In and S to form a tetrahedral coordination structure. The doping of Zn in the In-S tetrahedron makes the conduction band shift negatively, which is conducive to the redox reaction. Moreover, the transfer rate of electrons and holes is accelerated, which is beneficial to inhibit the recombination of electron-hole pairs. The optimized Zn-doped ZIS exhibits enhanced HER efficiency of 10.8 mmol/g/h under visible light, which is 2.9 times higher than that of the pristine ZIS.