Enhanced hydrogen evolution reaction of WS2–CoS2 heterostructure by synergistic effect

Transition metal dichalcogenides (TMDs) have attracted significant research interest due to its promising performance in hydrogen evolution reaction (HER). Synergistic effect between materials interface can improve the electrocatalytic properties. In this work, the WS₂–CoS₂ heterostructure supported on carbon paper (CP) was elaborately fabricated by a three-step method. Owing to the synergistic effect, WS₂–CoS₂ heterostructure exhibits an excellent electrocatalytic activity with a low overpotential of 245 mV at 100 mA/cm² and a small Tafel slope of 270 mV/dec toward HER. We demonstrate that the increased specific surface area and conductivity of the heterostructure play a key role in enhancing the overall catalytic efficiency. Moreover, the crystal lattice distortion in the heterostructure could induce charge redistribution and improve electron transfer efficiency, which may also benefit the whole HER activity.     

CoS2 with carbon shell for efficient hydrogen evolution reaction

In this study, we demonstrated the active electrocatalysts of CoS₂ coated by N-doped carbon microspheres, CoS₂@NHCs-x (x = 600, 700, 800, and 900; x is pyrolysis temperature). Results show that the obtained electrocatalyst has good catalytic activity and cyclic stability for the reaction of hydrogen evolution (HER) when the pyrolysis temperature is 800 °C. At a current density of 10 mA cm⁻², the overpotential of CoS₂@NHCs-800 was only 98 mV in 0.5 M H₂SO₄, and 118 mV in 1 M KOH, respectively. In addition, CoS₂@NHCs-800 also revealed excellent electrochemical stability, with only 32.7% performance degradation after continuous reaction in 0.5 M H₂SO₄ for 20 h, and the later current density almost no longer deceased with time as the reaction process stabilized. The excellent HER catalytic performance of CoS₂@NHCs-800 is mainly attributed to the rich active sites of CoS₂, the unique porous core-shell structure, and the enhanced conductivity of the carbon carrier caused by N and S co-doping. This work opens up an opportunity for advanced CoS₂-based electrocatalysts for HER.     

Metal–organic framework derived CoS2/FeS-MOF with abundant heterogeneous interface as bifunctional electrocatalyst for electrolysis of water

Highly active and stable non-precious metal dual-functional electrocatalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are very important for the industrialization of water electrolysis. Herein, a three-dimensional (3D) porous CoS₂/FeS-MOF with adjustable Co/Fe molar ratio are in-stiu grown on a nickel foam (NF) to get a binder-free electrocatalyst electrode for HER and OER (CoS₂/FeS-MOF@NF). It should be emphasized that the MOFs precursor forms abundant heterogeneous interfaces through in-situ sulfidation. Moreover, the open skeleton and ordered porous structure of MOFs will not be destroyed due to the low temperature. The redistribution of electrons at the heterogeneous interfaces will produce more catalytic active centers, providing more active sites for reactant molecules or intermediates, thus availably promoting the electrocatalytic activity of the composite. Therefore, the optimized catalyst CoS₂/FeS-MOF@NF-1 displays high OER activity. The overpotential is only 136 mV at 10 mA cm^?2. At the same time, the CoS₂/FeS-MOF@NF-1 also shows good HER catalytic activity. Therefore, the assembled corresponding symmetric electrolyzer CoS₂/FeS-MOF@NF-1||CoS₂/FeS-MOF@NF-1 achieves a low cell voltage of 1.5 V at 10 mA cm^?2 with long time stability for 24 h. This work provides a simple and convenient strategy for the synthesis of transition metal sulfides dual-function electrocatalysts.     

Self-adaptive amorphous Co2P@Co2P/Co-polyoxometalate/nickel foam as an effective electrode for electrocatalytic water splitting in alkaline electrolyte

Noble-metal-free transition metal based phosphides (TMPs) display great potential as candidates to replace the state-of-the-art noble metal-based catalysts for electronic water splitting. In this study, amorphous Co₂P was decorated on Co-polyoxometalate (POM) and conductive cobalt phosphide forming integrated Co₂P@ Co₂P/Co-POM/NF electrode, through in suit growth, low-temperature phosphating and electrocatalytic self-adaption pathway by the stripping of superficial Co-POM when subjected to persistent bubbles. The fantastic design simultaneously offers excellent electrical conductivity for fast electron transfer, a large surface area with numerous active edge sites and a conductive current collector facilitating mass transfer and gas release. The electrode showed high catalytic activity, requiring overpotential of 130 mV for HER to achieve a current density of 50 mA/cm², 336 mV for OER to achieve a current density of 50 mA/cm², affording a water-splitting current density of 10 mA/cm² at a low cell voltage of 1.6 V. The results and facile synthesis method also offer an exciting avenue for the design of amorphous phase TMPs on a current collector with high specific area and excellent electrical conductivity for energy storage and conversion devices.     

CoS2/MoS2 decorated with nitrogen doped reduced graphene oxide and multiwalled carbon nanotube 3D hybrid as efficient electrocatalyst for hydrogen evolution reaction

Designing an efficient and stable electrocatalyst made of earth abundant elements to take over expensive noble metal based for Hydrogen Evolution Reaction (HER) have been focused. Cobalt disulfide-molybdenum disulfide nanocomposite supported by nitrogen doped reduced graphene oxide and multiwalled carbon nanotubes (CoS₂/MoS₂@NrGO-MWCNT) is reported as an efficient electrocatalyst for HER. CoS₂/MoS₂@N-rGO-MWCNT and ternary hybrids composed of CoS₂, MoS₂ and N-rGO/MWCNT have been investigated. The catalysts were prepared by facile hydrothermal method, and the optimal doping ratio referred to date cobalt to molybdenum as 2:1 was chosen. It is found that co-existence of CoS₂, MoS₂ brings abundant active sites and incorporation of MWCNT offered stability. Good dispersion of CoS₂ nanoparticles on graphene and MoS₂ sheets is observed. Additionally nitrogen doping on rGO sheets has been carried out to boost up the electronegativity of the catalyst as a support to enhance the catalytic activity of CoS₂/MoS₂ for refine structure and better electrical conductance. Precisely, CoS2/MoS2@N-rGO-MWCNT exhibited smaller tafel slope 73 mV dec^?1 at overpotential 281 mV for current density 10 mA cm^?2 and the substantial stability of 14 h is recorded in 0.5 M H₂SO₄ medium, results suggest that catalyst is viable alternate for HER.     

Co3Mo3N nanosheets arrays on nickel foam as highly efficient bifunctional electrocatalysts for overall urea electrolysis

Replacing dynamics-restricted oxygen evolution reaction (OER) with smart urea oxidation reaction (UOR) is very important for reducing the power consumption for hydrogen production. Here, the Co₃Mo₃N-400/NF is prepared using a facial way, which exhibits remarkable catalytic performances for UOR, hydrogen evolution reaction (HER) and overall urea electrolysis (OUE) because of the more exposed active sites and high electrical conductivity. At 100 mA/cm², the Co₃Mo₃N-400/NF shows a small potential of 1.356 V vs. RHE (reversible hydrogen electrode) for UOR, which is much lower than that for OER. Furthermore, for HER, to reach to 100 mA/cm², a low overpotential of 299 mV is required, and the urea has negligible influence on the HER process. For OUE, the Co₃Mo₃N-400/NF||Co₃Mo₃N-400/NF shows a small cell potential of 1.481 V at 100 mA/cm² along with a good durability. Our work provides more choice for future OUE to generate hydrogen.     

A facile one-pot synthesis of microspherical-shaped CoS2/CNT composite as Pt-free electrocatalyst for efficient hydrogen evolution reaction

Hydrogen evolution reaction has been recognized as a green technology in the field of electrochemical energy conversion and storage devices. Nevertheless, it is necessary task to finding an economical and effective electrocatalysts for HER. Among the different HER catalysts, the cobalt disulfide (CoS₂) showed an excellent HER activity owing to its low cost, easy to synthesize and good stability. Hence, in this work, we prepared a series of CoS₂/CNT composites with different contents CNT from 4 to 12 wt% by a simple one-step hydrothermal method to investigate the influence of CNT on HER activity of CoS₂. The structural and morphological properties of the obtained samples were analyzed through XRD, SEM, HR-TEM, and XPS. The SEM images of CoS₂/CNT composite showed the spherical-shaped CoS₂ covered by the CNT nanostructure. In addition, the electrochemical tests were carried out using 0.5 M H₂SO₄ solution in order to assess their HER activity. The attained electrochemical results showed that the CoS₂/CNT composite with 8% CNT offers an outstanding HER activity with the smallest overpotential of 155 mV at 10 mA cm⁻² and lowest Tafel slope of 59 mV dec⁻¹ when compared with other composites. Also, the optimized CoS₂/CNT composite provided excellent stability in the acidic medium after 1000 cycles. Therefore, the as-synthesized CoS₂/CNT composite will be an efficient, low-cost and Pt-free electrocatalyst for HER application.     

Cu–Co–P electrodeposited on carbon paper as an efficient electrocatalyst for hydrogen evolution reaction in anion exchange membrane water electrolyzers

To solve the issues of energy shortage and environmental pollution, it is essential to develop highly effective catalysts for hydrogen evolution reaction (HER) in water electrolysis. Herein, we report a facile and rapid fabrication of a Cu–Co–P catalyst on a carbon paper (CP) substrate using electrodeposition. First, the deposition conditions for Co–P/CP were optimized. The prepared Co–P consisted of numerous spheres and exhibited acceptable catalytic activity towards HER in an alkaline medium with an overpotential of 72 mV at current density of ?10 mA/cm². Further performance enhancement was achieved by the incorporation of Cu to modify the electronic structure of the Co–P catalyst. In a half-cell test, the optimized Cu–Co–P/CP exhibits remarkable performance, achieving ?10 mA/cm² at an overpotential of 59 mV, and the Tafel slope is 38 mV/dec. In a single-cell test, an anion exchange membrane water electrolyzer with a Cu–Co–P/CP cathode and commercial IrO₂/CP anode exhibited high current density of 0.70 A/cm² at 1.9 V_cell.     

MoS2 supported CoS2 on carbon cloth as a high-performance electrode for hydrogen evolution reaction

Here we report a strategy to prepare electrocatalysts for hydrogen generation based on MoS₂ grown on highly conductive CoS₂ decorated carbon cloth (MoS₂/CoS₂/CC) through a two-step method. The rational design of sandwich structure of MoS₂/CoS₂/CC electrode was significant for homogenously dispersing MoS₂ on the carbon substrate, tuning the properties of the MoS₂ and improving long-term durability. Benefiting from the sandwich structure with highly exposed edges, fast electron transport and additional active sites brought by interfacial sulfur of MoSCo, the resulting MoS₂/CoS₂/CC electrode exhibited superior HER activity and excellent stability in acid solution including an overpotential of 118 and 159 mV at current density of 10 and 100 mA/cm², respectively, a Tafel slope of 37 mV per decade and excellent cycling stability in acid solution. The high catalytic performance and simplicity of the preparation method suggest applicability of the MoS₂/CoS₂/CC electrode for large-scale practical applications.     

Crystalline nickel sulfide integrated with amorphous cobalt sulfide as an efficient bifunctional electrocatalyst for water splitting

The development of highly efficient and low-cost electrocatalysts is critical to the mass production of hydrogen from water splitting. Herein, a facile yet effective method was developed to synthesize bimetallic sulfides Ni₃S₂/CoS_x, which were aimed for use as the electrocatalysts in both HER and OER. Encouragingly, the Ni₃S₂/CoS_x demonstrated a low overpotential of 110 mV for HER at a current density of 10 mA·cm^?2. It was discovered that the surface of Ni₃S₂/CoS_x during OER process would undergo an in-situ oxidation to form MOOH (M = Co, Ni), that is, MOOH/Ni₃S₂/CoS_x were the real functioning species in catalysis, which had an excellent OER activity and a low overpotential of 226 mV. Additionally, the assembled electrolyzer required only a low cell voltage of 1.53 V to achieve a current density of 10 mA·cm^?2 in a 1 M KOH solution, and its performance was stable. Overall, this work provided a promising strategy for the facile fabrication of low-cost amorphous electrocatalysts, which is expected to promote the progress of overall water splitting.     

PdCu bimetallic nanoparticles decorated on ordered mesoporous silica (SBA-15) /MWCNTs as superior electrocatalyst for hydrogen evolution reaction

In the present study, a novel electrocatalyst with excellent catalytic performance based on PdCu bimetallic nanoparticles (NPs) supported on ordered mesoporous silica and multi-walled carbon nanotubes (PdCu NPs/SBA-15-MWCNT) was prepared for electrochemical hydrogen evolution reaction (HER). For this purpose, low-cost mesoporous SBA-15 was synthesized using silica extracted from Stem Sweep Ash (SSA) as an economically attractive silica source. Mesoporous SBA-15 with unparalleled porous structure is a stable support for PdCu bimetallic NPs which prevents the accumulation of PdCu bimetallic NPs and improves its efficiency in the catalytic process. The main advantage of this strategy is low loading of bimetallic catalyst with high catalytic activity. The presence of both mesoporous SBA-15 and MWCNTs materials in PdCu/SBA15-MWCNTs/carbon paste electrode (CPE) increases the metallic active sites and the electrical conductivity of electrode which provides great performance for HER. PdCu/SBA15-MWCNTs-CPE provided small Tafel slope (45 mV dec^?1), low onset potential (~-150 mV), high current density (?165.24 mA cm^?2at -360 mV) and exchange current density (2.51 mA cm^?2) with great durability for HER in H₂SO₄ solution. Analysis of kinetic data suggests that the electrocatalyst controls HER by the Volmer-Heyrovsky mechanism. In addition, studies showed that the presence of sodium dodecyl sulfate (SDS) in electrolyte can decrease the potential of HER and increase the current density.     

The effect of annealing temperature,reaction time,and cobalt precursor on the structural properties and catalytic performance of CoS2 for hydrogen evolution reaction

In this study, cobalt disulfide (CoS₂) nanostructures are synthesized using a simple hydrothermal method. The effects of experimental parameters including cobalt precursor, reaction times, and reaction temperatures are investigated on the structure, morphology and electrocatalytic properties of CoS₂ for hydrogen evolution reaction (HER). The characterization of as-prepared catalysts is performed using X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), and X-ray photoelectron spectroscopy (XPS). The HER efficiency of the catalysts is examined using linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) methods in 0.5 M H₂SO₄ solution. Furthermore, chronoamperometry (CA) is used for stability evaluation. The catalyst obtained from cobalt acetate precursor, within 24 h at 200 °C exhibits superior electrocatalytic activity with a low onset potential (139.3 mV), low overpotential (197.3 mV) at 10 mA. cm^?2 and a small Tafel slope of 29.9 mV dec^?1. This study is a step toward understanding the effect of experimental parameters of the hydrothermal method on HER performance and developing optimal design approaches for the synthesis of CoS₂ as a common electrocatalyst.     

Ni–Zn nanosheet anchored on rGO as bifunctional electrocatalyst for efficient alkaline water-to-hydrogen conversion via hydrazine electrolysis

Bifunctional Ni-15 at.% Zn/rGO catalyst was fabricated by a two-step electrodeposition to be used for efficient alkaline water-to-hydrogen conversion via hydrazine electrolysis. Experiments show that the as-deposited Ni-15 at.% Zn/rGO nanosheet arrays with porous structure possesses excellent catalytic activity and stability towards both hydrogen evolution reaction (HER) and hydrazine oxidation reaction (HzOR). A small overpotential of 49 mV at 10 mA cm⁻² with a low Tafel slope of 26.3 mV dec⁻¹, and a retention rate of 91.4% after 12 h at 10 mA cm⁻² are observed for Ni-15 at.% Zn/rGO towards HER. Moreover, Ni-15 at.% Zn/rGO also shows an extra-high current density of 1097 mA cm⁻² at 0.6 V vs RHE with a low Tafel slope of 33.5 mV dec⁻¹, and a high durability of 90.5% after 5000 s towards HzOR. Moreover, two-electrode cell was constructed using Ni-15 at.% Zn/rGO as both cathode and anode for HER and HzOR, achieving 100 mA cm⁻² at an ultralow cell voltage of 0.418 V. The above outstanding bifunctional catalytic performance should be attributed to its large ECSA, high electrical conductivity and most importantly, its superaerophobic surface induced by the porous structure with nanosheet arrays.     

Hierarchical flower-like CoS2-MoS2 heterostructure spheres as efficient bifunctional electrocatalyst for overall water splitting

Electrochemical water splitting technique requires high-efficient bifunctional electrocatalysts to obtain large-scale hydrogen production for resolving the impending energy and environmental crisis. Herein, hierarchical flower-like CoS₂-MoS₂ heterostructure hybrid spheres grown on carbon cloth (CoS₂-MoS₂/CC) were prepared by sulfuring wheel-shaped polyoxometalate {Co₂₀Mo₁₆}. The as-prepared CoS₂-MoS₂/CC as bifunctional electrocatalyst manifests excellent alkaline oxygen evolution and hydrogen evolution activities with low overpotentials of 240 mV for OER and 60 mV for HER at 10 mA cm^?2, respectively. When assembled as two-electrode cell, CoS₂-MoS₂/CC delivers an extremely low cell-voltage of 1.52 V at 10 mA cm^?2 accompanied with remarkable long-term durability. Additionally, CoS₂-MoS₂/CC exhibits favorable overall-water-splitting performance in simulated seawater. The superior performance of CoS₂-MoS₂/CC should be ascribed to the optimized intrinsic electron structure via electron transfer from MoS₂ to CoS₂ along with the synergistic effect of well-exposed heterostructure interfaces and favorable diffusion channels. This work offers a practical strategy for exploring high-efficient bifunctional electrocatalysts for overall water splitting.     

Three-dimensional hierarchically porous iridium oxide-nitrogen doped carbon hybrid: An efficient bifunctional catalyst for oxygen evolution and hydrogen evolution reaction in acid

Active and durable acid medium electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are of critical importance for the development of proton exchange membrane (PEM) water electrolyser or Fuel cells. Herein, we report a facile method for the synthesis of 3D-hierarchical porous iridium oxide/N-doped carbon hybrid (3D-IrO₂/N@C) and its superior OER and HER activity in acid. In 0.5 M HClO₄, this catalyst exhibited remarkable activity towards OER with a low overpotential of 280 mV at 10 mA/cm² current density, a low Tafel slope of 45 mV/dec and ∼98% faradaic efficiency. The mass activity (MA) and turnover frequency (TOF) are found to be 833 mA/mg and 0.432 s⁻¹ at overpotential of 350 mV which are ∼32 times higher than commercial (comm.) IrO₂. The HER performance of this 3D-IrO₂/N@C is comparable with comm. Pt/C catalyst in acid. This 3D-IrO₂/N@C catalyst requires only 35 mV overpotential to reach a current density 10 mA/cm² with Tafel slope 31 mV/dec. Most importantly, chronoamperometric stability test confirmed superior stability of this catalyst towards HER and OER in acid. This 3D-IrO₂/N@C catalyst was applied as both cathode and anode for over-all water splitting and required only 1.55 V overpotential to achieve a current density of 10 mA/cm² in acid. The outstanding activity of the 3D-IrO₂/N@C catalyst can be attributed to a unique hierarchical porous network, high surface area, higher electron and mass transportation, synergistic interaction between IrO₂ and carbon support.     

Engineering the semiconducting CdS nanostructures by N-doped rGO for enhancing the adsorption sites: Promising electrocatalyst for hydrogen evolution reaction

The development of non-noble electrocatalysts for hydrogen production from water is of immense interest as it is clean and eco-friendly. The present work explores the electrocatalytic performance of morphologically varied CdS NPs synthesized using different sulphur source and ionic liquids via hydrothermal treatment, in catalyzing hydrogen evolution reaction (HER). The hierarchical flower shaped morphology denoted as CdS–N3 outperformed other prepared electrocatalysts with a Tafel slope value of 118 mV dec^?1 and a low overpotential 344 mV @ a current density of 10 mA/cm². However, the outperformed CdS–N3 catalyst when blended with N doped rGO, it showed a superior activity with a low overpotential of 201 mV at 10 mA/cm². The catalyst disclosed a small Tafel slope of 70 mV dec^?1 corroborating that the catalyst contains more electroactive sites and oxygen vacancy voids for the adsorption-desorption of charge carriers generated from the heteroatom doping. The CdS/N-rGO catalyst also revealed a higher TOF value of 5.18 × 10^?3 s^?1, which further proves that catalyst is more efficient in releasing H₂ molecules and this findings affirms that CdS/N-rGO catalyst can be an efficient candidate for initiating HER kinetics with endurable stability in acidic medium for high purity hydrogen production.     

Defective-MoS2/rGO heterostructures with conductive 1T phase MoS2 for efficient hydrogen evolution reaction

As a two-dimensional material, molybdenum disulfide (MoS₂) exhibits great potential to replace metal platinum-based catalysts for hydrogen evolution reaction (HER). However, poor electrical conductivity and low intrinsic activity of MoS₂ limit its application in electrocatalysis. Herein, we prepare a defective-MoS₂/rGO heterostructures material containing 1T phase MoS₂ and evaluate its HER performance. The experimental results shown that defective-MoS₂/rGO heterostructures exhibits outstanding HER performance with a low overpotential at 154.77 mV affording the current density of 10 mA cm^?2 and small Tafel slope of 56.17 mV dec^?1. The unique HER performance of as-prepared catalyst can be attributed to the presence of 1T phase MoS₂, which has more active sites and higher intrinsic conductivity. While the defects of as-prepared catalyst fully expose the active sites and further improve catalytic activity. Furthermore, the interaction between MoS₂ and rGO heterostructures can accelerate electron transfer kinetics, and effectively ensure that the obtained catalyst displays excellent conductivity and structural stability, so the as-prepared catalyst also exhibits outstanding electrochemical cycling stability. This work provides a feasible and effective method for preparation of defective-MoS₂/rGO heterostructures, which also supplies a new strategy for designing of highly active and conductive catalysts for HER.     

Nanostructure and stoichiometry tailoring of CoS2 for high performance hydrogen evolution reaction

Developing efficient and low-cost electrocatalysts for hydrogen evolution reaction (HER) is important for hydrogen fuel production. In this study, we synthesized two different types of CoS₂ under low sulfur (LS) and high sulfur concentration (HS) conditions. Structural analysis results show that CoS impurity phase forms easily when the concentration of sulfur is low, while at high sulfur concentration the growth of CoS impurity phase is inhibited and leads to phase-pure CoS₂. Electrochemical investigation of HER performance reveals that the onset potential of CoS₂ (HS) electrode (ca. − 0.11 V vs. the reversible hydrogen electrode, RHE) is 30 mV anodic of the CoS₂ (LS) one (ca. − 0.14 V vs. RHE). At a specific current density of 10 mA cm⁻² the required overpotential on CoS₂ (HS) electrode is only 163 mV, which is 40 mV less than the CoS₂ (LS) electrode. Electrochemical impedance spectroscopy (EIS) data further demonstrate that the charge transfer rate of CoS₂ (HS) electrode is faster than that of CoS₂ (LS) electrode towards HER.     

Multi-shelled CoS2–MoS2 hollow spheres as efficient bifunctional electrocatalysts for overall water splitting

The exploration of highly efficient non-precious electrocatalysts is essential for water splitting devices. Herein, we synthesized CoS₂–MoS₂ multi-shelled hollow spheres (MSHSs) as efficient electrocatalysts both for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) using a Schiff base coordination polymer (CP). Co-CP solid spheres were converted to Co₃O₄ MSHSs by sintering in air. CoS₂–MoS₂ MSHSs were obtained by a solvothermal reaction of Co₃O₄ MSHSs and MoS₄²⁻ anions. CoS₂–MoS₂ MSHSs have a high specific surface area of 73.5 m²g^-1. Due to the synergistic effect between the CoS₂ and MoS₂, the electrode of CoS₂–MoS₂ MSHSs shows low overpotential of 109 mV with Tafel slope of 52.0 mV dec⁻¹ for HER, as well as a low overpotential of 288 mV with Tafel slope of 62.1 mV dec⁻¹ for OER at a current density of 10 mA cm⁻² in alkaline solution. The corresponding two-electrode system needs a potential of 1.61 V (vs. RHE) to obtain anodic current density of 10 mA cm⁻² for OER and maintains excellent stability for 10 h.     

Phosphorus-doping induced electronic modulation of CoS2–MoS2 hollow spheres on MoO2 film-Mo foil for synergistically boosting alkaline hydrogen evolution reaction

Combination of anionic doping and multicomponent synergism are effective approach to improve the performance of electrocatalysts toward hydrogen evolution reaction (HER) process. Herein, P-doped CoS₂–MoS₂ hollow spheres assembled by countless sheets on oxidized Mo foil (P–CoS₂/MoS₂/MoO₂) was synthesized by hydrothermal and phosphorization process. The unique hollow structure with countless sheets as wall endows more accessible active sites, fast electron/mass transport and high conductivity. P-doping could redistribute the local charge density and optimize the surface charge state to improve the intrinsic activity and accelerate reaction kinetics. The optimized P–CoS₂/MoS₂/MoO₂ exhibits an outstanding HER performance with an overpotential of 85 mV to reach 10 mA cm⁻², a small Tafel slope of 84.6 mV dec⁻¹, superior intrinsic HER activity and robust durability under alkaline solution. This work proposed a feasible strategy to build the hollow, heterostructured and binder-free electrode in renewable energy application.