Photocatalytic Hydrogen Evolution Reaction Performance Research Articles

Theory-Guided Experimental Design of Covalent Triazine Frameworks for Efficient Photocatalytic Hydrogen Production.

The high crystalline covalent triazine framework-1 (CTF-1), composed of alternating triazine and phenylene, has emerged as an efficient photocatalyst for solar-driven hydrogen evolution reaction (HER). However, it is of great challenge to further improve photocatalytic HER performance via increasing crystallinity due to its near-perfect crystallization. Herein, an alternative strategy of scaffold functionalization is employed to optimize the energy band structure of crystalline CTF-1 for boosting hydrogen-evolving activity. Guided by the computational predictions, versatile CTF-based polymer photocatalysts are prepared with different functional groups (OH, NH2, COOH) using binary polymerization for practical hydrogen production. Experiment evidence verifies that the introduction of a limited number of electron-donating groups is sufficient to maintain high crystallinity in CTF, modulate the band structure, broaden visible light absorption, and consequently enhance its photophysical properties. Notably, the functionalization with OH exhibits the most positive effect on CTF-1, delivering a photocatalytic activity with a hydrogen-producing rate exceeding 100µmol h-1.

In-situ decorated cobalt phosphide cocatalyst on Hittorf's phosphorus triggering efficient photocatalytic hydrogen production

Hittorf's phosphorus (HP) is a promising visible-light-driven photocatalyst, yet the slow charge migration and sluggish surface reaction kinetics have limited its photocatalytic hydrogen evolution reaction (HER) efficiency. In this work, cobalt phosphide (CoP2) modified rod-like HP (HP/CoP2) composite was designed and synthesized by a template-assisted chemical vapor deposition strategy. The optimal HP/CoP2 composite yields a HER rate reaching 13.1 μmol·h-1 through pure water splitting under visible light irradiation, which is approximately 4 times higher than that of HP using Pt as cocatalyst (3.3 μmol·h-1). It was experimentally indicated that the accelerated photogenerated charge transfer and promoted surface HER kinetics in the composite gave rise to the superior photocatalytic HER performance.

Heterostructure with tightly-bound interface between In2O3 hollow fiber and ZnIn2S4 nanosheet toward efficient visible light driven hydrogen evolution

Visible-light-driven photocatalytic hydrogen evolution is considered as one of the most useful approaches to produce renewable fuels from abundant resources. Indium oxide (In2O3) has attracted much attention in the field of solar hydrogen production due to its moderate band gap, which can be driven by visible light easily. However, the efficiency of hydrogen evolution reaction (HER) of In2O3 is currently unsatisfactory. To enhance the HER efficiency of In2O3, herein, sandwich-structured In2O3/ZnIn2S4 heterostructure was precisely constructed via in-situ growth of ZnIn2S4 nanosheets on the In2O3 hollow fibers. The fabricated In2O3/ZnIn2S4 heterostructure exhibited a significantly enhanced photocatalytic HER activity of 2.18 mmol/g/h as compared to pure In2O3 and ZnIn2S4. Such efficient photocatalytic hydrogen production is attributed to the tightly-bound interface between (001) planes of flake ZnIn2S4 and (222) planes of In2O3. Experimental and theoretical investigation indicates compactly interface enabling efficient charge transfer and separation, which benefited the excellent photocatalytic HER performance.

S vacancies engineering ZnIn2S4 nanosheets for boosted photocatalytic hydrogen evolution

2D-layered ZnIn2S4 nanosheets (ZIS NSs) have been considered as a promising photocatalysts to produce H2. Nevertheless, the carrier recombination of 2D ZnIn2S4 is still severe, which limits its photocatalytic efficiency and practical applications. Herein, the defective ZnIn2S4 nanosheets with S vacancies (DZIS NSs) is fabricated via an easy one-step solvothermal process only by changing the used solvent without a complex physical or/and chemical secondary treatment, which can realize efficient photocatalytic H2 generation. The resultant DZIS NSs show enhanced photocatalytic hydrogen evolution reaction (HER) activity and well stability after 5 cycles. And the photocatalytic HER rate of DZIS NSs is up to 5437 μmol−1 h−1 g−1, nearly 2.6 times of pristine ZIS NSs (2090 μmol−1 h−1 g−1). The experimental data suggest that the excellent photocatalytic HER performance of DZIS NSs is attributable to the existence of S vacancies, which can form a S defect energy level under the lower conduction band (CB), offering abundant active sites for hydrogen activation, extending the visible light absorption range and narrowing the bandgap of DZIS NSs. Such defect engineering strategy opens new avenues for other sulfide photocatalysts to further boost photocatalytic activity.

Single‐Atom Co‐Ultrafine RuOx Clusters Codecorated TiO2 Nanosheets Promote Photocatalytic Hydrogen Evolution: Modulating Charge Migration, H+ Adsorption, and H2 Desorption of Active Sites

AbstractRu as a cocatalyst has attracted wide attention as a substitute for Pt precious metal. However, the strong interaction between Ru and H atoms reduces the efficiency of hydrogen (H2) desorption and slows the overall hydrogen evolution reaction (HER) efficiency. How to further improve the efficiency of Ru‐based cocatalyst is challenging. Herein, single‐atom Co‐ultrafine RuOx clusters codecorated TiO2 nanosheets for photocatalytic HER are synthesized using a simple hydrothermal–calcination method. Experiments and theoretical calculations demonstrate that Co atoms can serve as a specific electronic medium, promoting electron enrichment at RuOx, thereby enhancing the adsorption of H+. Moreover, the electronic state of the interaction between adjacent Co atoms and RuOx is conducive to the desorption of H2. As a result, the proposed photocatalyst system gives a classy photocatalytic HER performance. The hydrogen production rate at stationary point reaches up to 20.20 mmol g−1 h−1, and the apparent quantum yield at 365 nm is 86.5%. It is worth noting that the hydrogen production rate in seawater is as high as 9.83 mmol g−1 h−1. This work offers precise guidance to design catalysts for efficient photocatalytic H2 production from the in‐depth understanding of the electronic coupling effect of coupling active sites.

Computational prediction of two-dimensional o-Al2N2 under applied strain for boosting the photocatalytic hydrogen evolution reaction performance

Photocatalytic water splitting for clean hydrogen fuel production provides a promising approach to solve the energy and environmental issues. Recently, two-dimensional (2D) photocatalysts have attracted growing interest owing to their short carrier diffusion path, abundant active sites and large surface area. This study explores the photocatalytic performance of 2D orthorhombic dialuminum dinitride (o-Al2N2) using density functional theory. The computational results show that the o-Al2N2 monolayer has a semiconductor character with indirect and moderate bandgap. Moreover, this system exhibits high light absorption in the visible region, referring to its high capacity for harvesting sunlight. Meanwhile, under neutral pH, the band edge positions are suitable to straddle water redox potentials and the hydrogen evolution reaction is energetically favorable to allow hydrogen production on the surface of 2D o-Al2N2 compound. More importantly, the photocatalytic activity of o-Al2N2 monolayer is significantly improved under slight biaxial compressive strain. Therefore, our findings suggest that the o-Al2N2 nanomaterial is a highly efficient 2D photocatalyst for hydrogen production via water splitting under neutral pH.

Synergism of electronic structure regulation and interface engineering for boosting hydrogen evolution reaction on S-Scheme FeS2/S-ZnSnO3 heterostructure

The customization of the photocatalyst's composition and structure to achieve enhanced hydrogen (H2) evolution performance is still a major challenge. Herein, FeS2/S-ZnSnO3 (FeS2@S-ZSO) heterostructure was constructed for efficient photocatalytic hydrogen evolution reaction (HER) activity. The band structure of ZnSnO3 was regulated by sulfur doping (S-ZSO), followed by coupling with FeS2 nanoparticles to form a composite enabling improved optical absorption range and efficient spatial separation/transfer of photogenerated carriers. The HER performance of the optimal heterostructure (8.7%FeS2@S15%-ZSO) achieved 2225 μmol g-1 h-1, which was 14.4, 5 and 12.6 times greater than ZSO, S15%-ZSO and FeS2, respectively. DFT-based calculations further validated that S doping regulates the electronic structure of S-ZSO, while the coupling of FeS2 constructs a S-Scheme heterostructure, which accelerates the carrier separation and transport dynamics resulting in the improvement of the HER performance. This study presents a novel approach to improve the photocatalytic HER performance of wide bandgap semiconductors through electronic structural regulation and interface engineering approaches.

Panchromatic Pt/TiO2-Based Photocatalysts Sensitized with Carboxylated Chlorin Dyads for Water Splitting Hydrogen Evolution

Harvesting and converting solar energy into hydrogen production provides a new strategy for the global energy crisis. Since TiO2, the most widely used photocatalyst, absorbs light limited in ultraviolet region, extension of photo-response in visible to near-infrared region by dye-sensitization of TiO2 photocatalysts has attracted more and more attention in the field of artificial photosynthesis. In this work, three chlorophyll(Chl)-related sensitizers were designed to realize panchromatic light-absorption to simulate the charge separation process in natural photosynthetic reaction centers. The dyad sensitizers were synthesized by covalently-linking two different types of chromophore units derived from natural Chls-a/b, and their effects of Pt/TiO2-based photocatalysts for water splitting hydrogen evolution reaction (HER) were investigated. The Pt/TiO2 composite sensitized with Chl-a type dyad showed the best photocatalytic HER performance, and the H2 evolution of 5.4 mmol g-1h-1 was achieved. Electronic absorption, fluorescence emission, and time-resolved photoluminescence spectra as well as photocurrent responses and electrochemical impedance measurements were used to reveal the key factors of dyad sensitizers that influence the performances of Pt/TiO2 based photocatalysts. This work provides insights to explore new organic dye-sensitizers for improving the performance of TiO2-based photocatalysts.

Enhanced photocatalytic hydrogen evolution by piezoelectric effects based on MoSe2/Se-decorated CdS nanowire edge-on heterostructure

The build-in electric field by the construction of heterojunction is one of the most promising strategies to suppress the recombination of photogenerated carriers. Here, we reported a piezo-photocatalytic system composed of Se-decorated CdS nanowires and few-layered edge-on MoSe2 nanosheets for efficient H2 generation by two-pot hydrothermal synthesis. The few-layered MoSe2 exposed abundant edge sites for hydrogen evolution reaction (HER). The activity of 20-MoSe2/CdS0.95Se0.05 (20-MS/CSS, with 20 mol% of MoSe2 loading) nanocomposite casted a remarkable photocatalytic HER performance, with a rate of 47.3 mmol h−1 g−1. Moreover, MoSe2 nanosheets deformed to generate the piezoelectric polarization field under magnetic stirring, which rendered efficient separation of photogenerated carriers, resulting in a piezo-photocatalytic synergistic effect. As a result, the HER of 20-MS/CSS at 900 rpm for piezo-photocatalysis was 59.1 mmol h−1 g−1, which was 1.25 times that of 20-MS/CSS for photocatalysis. Meanwhile, the photoelectrochemical measurements further visualized the piezo-photoelectric synergy. This study exposes a new way for utilizing mechanical energy to improve photocatalytic performance, and achieving high piezo-photocatalysis.

Improved atomic hydrogen desorption by Cu3N with suitable electronic structure to enhance photocatalytic H2 evolution

Photocatalytic hydrogen evolution reaction (HER) using solar energy as a driving force is considered to be one of the most promising approaches to alleviate energy and environmental problems. However, the problem of low solar conversion efficiency resulted from the easy recombination of photogenerated electron-hole pairs in semiconductor catalysts needs to be solved urgently. Theoretical calculations were firstly taken to prove that copper nitride (Cu3N) exhibits a matched D-band center position and hydrogen adsorption Gibbs free energy (ΔGH∗), which can improve the H2 adsorption/desorption balance and then achieve an effective promotion of photogenerated charge kinetics. Cu3N was herein chosen as a co-catalyst to enhance photocatalytic HER performance. Two-dimensional carbon nitride (2D CN) was chosen as the catalyst due to the layer structure which could shorten electronic transmission distance. The results showed that the HER activity of Cu3N/2D CN is 117 times higher than that of 2D CN (2721.55 vs. 23.18 μmol/g/h) and an apparent quantum yield of 3.78% at 420 nm. Compared with other Cu(I)-based composite catalysts, Cu3N/2D CN also exhibits the highest HER activity. This work investigates the transfer process of photogenerated carriers and reveals the photocatalytic mechanism through a combination of theoretical calculations and experimental characterization.

Tuning metal-support interaction of NiCu/graphene cocatalysts for enhanced dye-sensitized photocatalytic H2 evolution

The modulation of metal-support interaction (MSI) is of particular interest in improving the catalytic performance of metal nanocatalysts. Herein, we adopt an alloying strategy to tune the MSI in graphene-supported Ni catalyst by introducing Cu. The NiCu/graphene cocatalysts (denoted as NxCyG) are facilely synthesized by directly calcinating the mixture of metal chlorides and graphene oxide for dye-sensitized photocatalytic hydrogen evolution reaction (HER). The results reveal the introduction of Cu significantly affects the MSI in NxCyG cocatalysts, and a reasonable Ni/Cu ratio (4:1) significantly enhances the MSI in N4C1G cocatalyst. Such an enhanced MSI facilitates the electron injection from excited dye to RGO and further transfer to the NiCu alloy, and leads to smaller size of NiCu alloy nanoparticles (NPs) with sufficient active sites. Moreover, the synergetic effect between Ni and Cu is conducive to optimize the hydrogen adsorption on NiCu surface. As a result, the N4C1G cocatalyst shows much improved electrocatalytic and photocatalytic HER performance compared with monometallic Ni/graphene and Cu/graphene. The apparent quantum yield (AQY) at 420 nm reaches up to 67.7 % in the dye-sensitization system. We believe that this work develops a facile and effective strategy to tune the MSI of metal/graphene catalysts for enhanced HER performance.

Realization of all-in-one hydrogen-evolving photocatalysts via selective atomic substitution

Major challenges of realization of all-in-one hydrogen-evolving photocatalysts are the relatively poor charge separation efficiency and unfavorable hydrogen desorption properties owing to the strong correlation between the catalytic site and adsorbed H. Herein, an example of Ni doped few-layer ZnIn2S4 nanosheets (Ni-ZnIn2S4) is carried out to deeply understand the role of Ni dopant in tailoring the charge separation efficiency and weakening the bond energy between electronegative S sites and adsorbed H (S-Hads). Our theoretical calculations demonstrate that Ni ions preferentially incorporates into tetrahedral Zn sites rather than tetrahedral/octahedral In sites, which endows Ni-ZnIn2S4 with improved electronic conductivity and more delocalized charge carriers involved in hydrogen evolution reaction (HER). More importantly, Ni dopants can be capable of exquisitely altering the electronic structure of S sites, leading to a balanced hydrogen adsorption and desorption ability. Consequently, the as-prepared few-layer Ni-ZnIn2S4 nanosheets enable long-lived photo-excited electrons and enhanced photocatalytic HER performance.

Graphene quantum dot with covalently linked Rhodamine dye: a high efficiency photocatalyst for hydrogen evolution

Designing metal free photocatalyst for solar water splitting is an emerging field of research. Although graphene quantum dot (GQD) has been explored as a potential photocatalyst, their performance remains inherently limited by poor visible light absorption and p-type conductivity. To address this problem, we have covalently functionalized GQD with visible light active photosensitizer Rhodamine 123. It was found that this dye-sensitized GQD could make quite stabilized photocatalytic hydrogen evolution reaction (HER) under visible light irradiation, which is in striking contrast to the virtually inactive photocatalytic HER performance of control GQD without dye. Efficient photo-induced electron transfer from Rhodamine 123 to GQD and also the transformation of p type GQD to the n-p ambipolar semiconductor, both boosted by covalent bonding, are responsible for such high photocatalytic HER performance. Observation of negative photocurrent at zero bias voltage during transient photocurrent measurement, also suggests its promising potential in the metal free photocathode system to achieve photoelectrochemical H2 production.

Porous Ni5P4 as a promising cocatalyst for boosting the photocatalytic hydrogen evolution reaction performance

Nonmetallic cocatalysts have demonstrated unprecedented potential for accelerating photocatalytic hydrogen evolution reaction (HER). In this study, a nickel phosphide compound, namely Ni5P4, with porous carnation-like superstructure has been target-synthesized and then employed as HER cocatalyst to in-situ build a hybrid with protonated g-C3N4 nanosheets via an electrostatic self-assembly method. Owing to the synergistic advantages of the excellent metallic conductivity and porous carnation-like superstructure of Ni5P4, the as-obtained HCN/Ni5P4 Schottky-junction with abundant active sites, low H* atom adsorption energy and efficient charge carrier transport channel, affords the photocatalytic H2 production rate of 1157.5 μmol g−1 h−1 when exposed to visible light (λ > 420 nm). This photocatalytic H2 production rate was much higher than those of the corresponding reference cocatalysts, namely Ni2P and NiS2 (169.1 and 593.1 μmol g−1 h−1, respectively), both of which were derived from the same Ni(OH)2 precursor. This study provides a new idea for the design of highly active noble-metal-free materials for the photocatalytic HER.

Large‐Size, Porous, Ultrathin NiCoP Nanosheets for Efficient Electro/Photocatalytic Water Splitting

AbstractPorous ultrathin 2D catalysts are attracting great attention in the field of electro/photocatalytic hydrogen evolution reaction (HER) and overall water splitting. Herein, a universal pH‐controlled wet‐chemical strategy is reported followed by thermal and phosphorization treatment to prepare large‐size, porous and ultrathin bimetallic phosphide (NiCoP) nanosheets, in which graphene oxide is adopted as a template to determine the size of products. The thickness of the resultant NiCoP nanosheets ranges from 3.5 to 12.8 nm via delicately adjusting pH from 7.8 to 8.5. The thickness‐dependent electrocatalytic performance is evidenced experimentally and explained by computational studies. The prepared large‐size ultrathin NiCoP nanosheets show excellent bifunctional electrocatalytic activity for overall water splitting, with low overpotentials of 34.3 mV for HER and 245.0 mV for oxygen evolution reaction, respectively, at 10 mA cm−2. Furthermore, the NiCoP nanosheets exhibit superior photocatalytic HER performance, achieving a high HER rate of 238.2 mmol h−1 g−1 in combination with commonly used photocatalyst CdS, which is far superior to that of Pt/CdS (81.7 mmol h−1 g−1). All these results demonstrate large‐size porous ultrathin NiCoP nanosheets as an efficient and multifunctional electro/photocatalyst for water splitting.

A [001]-Oriented Hittorf's Phosphorus Nanorods/Polymeric Carbon Nitride Heterostructure for Boosting Wide-Spectrum-Responsive Photocatalytic Hydrogen Evolution from Pure Water.

Red phosphorus is a promising photocatalyst with wide visible-light absorption up to 700 nm, but the fast charge recombination limits its photocatalytic hydrogen evolution reaction (HER) activity. Now, [001]-oriented Hittorf's phosphorus (HP) nanorods were successfully grown on polymeric carbon nitride (PCN) by a chemical vapor deposition strategy. Compared with the bare PCN and HP, the optimized PCN@HP hybrid exhibited a significantly enhanced photocatalytic activity, with HER rates reaching 33.2 and 17.5 μmol h-1 from pure water under simulated solar light and visible light irradiation, respectively. It was theoretically and experimentally indicated that the strong electronic coupling between PCN and [001]-oriented HP nanorods gave rise to the enhanced visible light absorption and the greatly accelerated photoinduced electron-hole separation and transfer, which benefited the photocatalytic HER performance.

A [001]‐Oriented Hittorf's Phosphorus Nanorods/Polymeric Carbon Nitride Heterostructure for Boosting Wide‐Spectrum‐Responsive Photocatalytic Hydrogen Evolution from Pure Water

AbstractRed phosphorus is a promising photocatalyst with wide visible‐light absorption up to 700 nm, but the fast charge recombination limits its photocatalytic hydrogen evolution reaction (HER) activity. Now, [001]‐oriented Hittorf's phosphorus (HP) nanorods were successfully grown on polymeric carbon nitride (PCN) by a chemical vapor deposition strategy. Compared with the bare PCN and HP, the optimized PCN@HP hybrid exhibited a significantly enhanced photocatalytic activity, with HER rates reaching 33.2 and 17.5 μmol h−1 from pure water under simulated solar light and visible light irradiation, respectively. It was theoretically and experimentally indicated that the strong electronic coupling between PCN and [001]‐oriented HP nanorods gave rise to the enhanced visible light absorption and the greatly accelerated photoinduced electron–hole separation and transfer, which benefited the photocatalytic HER performance.

Versatile Functional Porous Cobalt-Nickel Phosphide-Carbon Cocatalyst Derived from a Metal-Organic Framework for Boosting the Photocatalytic Activity of Graphitic Carbon Nitride.

Metal-organic framework-templated g-C3N4-NiCoP2-porous carbon (PC) ternary hybrid nanomaterials were designed by taking full advantage of the metal-organic framework (MOF) derivative in the photocatalytic reaction for the first time. The MOF-templated porous structure could prevent the stacking of the carbon nitride nanosheet, and the carefully designed NiCoP2, possessing low electrocatalytic hydrogen evolution reaction (HER) overpotential and flat-band potential, could improve the separation as well as the utilization efficiency of photogenerated electron-hole pairs. Moreover, the ligand-templated porous carbon, acting as an interface mediator between g-C3N4 and the NiCoP2 cocatalyst, could boost the charge carrier transport. Consequently, the optimal ternary g-C3N4-NiCoP2-PC heterostructure exhibited enhanced photocatalytic HER performance and considerable H2 evolution performance of 5.8 μmol/h/g under UV-visible light with stoichiometric H2O2 production even in pure water. This work took full advantage of the MOF derivative for improving the photocatalytic reaction activity and provided a method that can hopefully help in designing a novel high-performance catalyst for solar conversion.

Amorphous Bimetallic Cobalt Nickel Sulfide Cocatalysts for Significantly Boosting Photocatalytic Hydrogen Evolution Performance of Graphitic Carbon Nitride: Efficient Interfacial Charge Transfer.

Noble metals usually work as the cocatalyst for photocatalytic water splitting, but their rare and expensive properties narrowed their wide development. Transition-metal sulfides have appeared to be promising non-noble metal cocatalysts in the hydrogen evolution reaction (HER) to meet future energy demands. Meanwhile, many studies focus on the fabrication of bimetallic catalysts because of their remarkably superior catalytic activity compared with monometallic substances. Herein, amorphous bimetallic cobalt nickel sulfide (CoNiSx) was fabricated to work as a cocatalyst in the photocatalytic H2 evolution reaction, which can couple with pristine graphitic carbon nitride (g-C3N4). CoNiSx-CN exhibits a larger specific surface area compared with g-C3N4, making it possess more reaction active sites. Moreover, the contacted interface in the CoNiSx-CN composite photocatalyst contributes to higher separation efficiency of photogenerated carriers, which was proved by experimental and theoretical calculations. More importantly, the theoretical calculation also verified that CoNiSx-CN has relatively closer Gibbs free energy to zero than pure g-C3N4 and corresponding monometallic cocatalyzed g-C3N4. Therefore, the prepared CoNiSx-CN composite exhibited a dramatic photocatalytic HER performance of 2.366 μmol mg-1 h-1, which is about 76-fold higher in comparison with pristine g-C3N4 and comparable to g-C3N4 with Pt as a cocatalyst under 420 nm light irradiation. This study reveals a promising and efficient bimetallic cocatalyst for the photocatalytic H2 evolution reaction.

Phase controlled synthesis and the phase dependent photo-and electrocatalysis of CdS@CoMo2S4/MoS2 catalyst for HER

Herein we report a heterostructure with ultrathin nanosheets of Co-doped molybdenum sulfide on CdS nanorod array (donated as CdS@CoMo2S4/MoS2) by hydrothermal synthesis. Firstly, elemental Co doping MoS2 (CoMo2S4) delivers the double benefits of increased active sites and enhanced conductivity. Secondly, the structural characteristics maximally exposes the MoS2 edges and enlarges interfacial contact area between the composite catalyst and electrolyte, as well as the efficient interfacial charge transfer. The ratio of CoMo2S4/MoS2 in CdS@CoMo2S4/MoS2 plays a crucial role for the enhanced photo-assistant electrocatalytic hydrogen evolution reaction (HER). We can tune the ratio of CoMo2S4/MoS2 by controlling the preparation time or the ratio of precursor of Co/Mo. The catalyst with predominant MoS2 phase shows superior photocatalytic HER performance with a high H2 production rate of 46.60 μmol mg−1 h−1. Meanwhile, the catalyst with predominant CoMo2S4 phase exhibits not only relatively low overpotential of 172 mV at 10 mA cm−2, which outperforms most values that have been reported on catalyst supported on ITO substrate, but also possesses H2 production rate of 23.47 μmol mg−1 h−1. The superior photo-assistant electrocatalytic HER activity results from the synergistically structural and electronic modulations, as well as the proper energy band alignment between MoS2 and CdS. This investigation could provide an approach to integrate the electro- and photocatalytic activities for HER, especially the photo responding behaviour at a bias potential which is meaningful to produce H2 for actual application.