Ultra-fine Ru nanoparticles decorated V2O3 as a pH-universal electrocatalyst for efficient hydrogen evolution reaction

Developing high-efficiency electrocatalysts viable for pH-universal hydrogen evolution reaction (HER) has attracted great interest because hydrogen is a promising renewable energy carrier for replacing fossil fuels. Herein, we present a facile strategy for fabricating ultra-fine Ru nanoparticles (NPs) decorated V₂O₃ on the carbon cloth substrates as efficient and stable pH-universal catalysts for HER. Benefiting from the metallic property and electronic conductivity of V₂O₃ matrix, the optimized hybrid (Ru/V₂O₃-CC) exhibits excellent HER activities in a wide pH range, achieving lower overpotentials of 184, 219, and 221 mV at 100 mA cm⁻² in 0.5 M H₂SO₄, 1.0 M KOH and 1.0 M phosphate-buffered saline, respectively. Moreover, the electrode remains superior stability with negligible degradation after 5000 cyclic voltammetry scanning whether in acidic, alkaline or neutral media. Experimental results, combined with theoretical calculations, demonstrate that the interaction between Ru NPs and the support V₂O₃ induces the local electronic density diversity, allowing optimization of the adsorption energy of Ru towards hydrogen intermediate H1, thus favoring the HER process.     

Facile synthesis of carbon encapsulated RuO2 nanorods for supercapacitor and electrocatalytic hydrogen evolution reaction

In this work, carbon encapsulated RuO₂ nanorods (RuO₂ NRs/C) has been synthesized by thermolysis of ruthenium chloride and Punica granatum (P. granatum) peel under N₂ atmosphere. The synthesized RuO₂ NRs/C was characterized using Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction method (XRD), field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HR-TEM) with energy dispersive spectroscopy (EDS) analyses. The FT-IR results suggested that the organic constituents of P. granatum have been carbonized and encapsulated over RuO₂ nanorods (RuO₂ NRs). The XRD pattern of RuO₂ NRs/C revealed its crystalline nature and carbon encapsulation. The synthesized RuO₂ NRs/C has been well dispersed with the average width of 20 nm, exposed from the FE-SEM and HR-TEM images. The EDS results of RuO₂ NRs/C showed the existence of three elements viz., Ru, O and C. Further, the supercapacitor and electrocatalytic hydrogen evolution reaction (HER) activities of RuO₂ NRs/C were studied using standard electrochemical methods. The synthesized RuO₂ NRs/C offered a maximum specific capacitance of 151.3 F g⁻¹ at a scan rate of 5 mV s⁻¹, obtained from the cyclic voltammetry results. The onset over potential and Tafel slope of synthesized RuO₂ NRs/C for HER were −0.099 V_RHE and −99.4 mV dec⁻¹, respectively. The present study revealed that RuO₂ NRs/C as a better candidate for supercapacitor and HER.     

Biomass-derived carbon nanosheets coupled with MoO2/Mo2C electrocatalyst for hydrogen evolution reaction

Transition metal carbide such as molybdenum carbide has been widely used in electrolytic water for hydrogen production due to its potential catalytic property. The synthesis of molybdenum carbide-based high-efficient catalysts by simple process remains great challenges. Herein, Mo oxide/carbide material with hybrid morphology was synthesized by carbonizing mixture of lotus roots and Mo salt. The as-obtained material consists of MoO₂/Mo₂C (MOMC) anchored on biomass-derived nitrogen-doped carbon (NC) matrix. The results show that as-prepared material displays leaf-like and belt-like nanosheets, and the MOMC/NC catalyst with optimal Mo contents exhibits an excellent activity with a low overpotential of 138 mV to drive 10 mA cm^?2 and Tafel slope is 56.7 mV dec^?1 in alkaline medium, indicating that as-prepared catalyst will have promising application in the field of catalysis.     

Electrocatalytic performance of carbon dots/palladium nanoparticles composite towards hydrogen evolution reaction in acid medium

In this work, nitrogen doped carbon dots (NDCDs) and nitrogen doped carbon dots supported palladium nanoparticles composite (n-Pd@NDCDs) were synthesized through hydrothermal carbonization and thermolytic reduction using Morinda citrifolia (M. citrifolia) fruit and palladium chloride as carbon and Pd precursors, respectively. The synthesized materials viz., n-Pd@NDCDs and NDCDs were duly characterized by high resolution transmission electron microscopy (HR-TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). The optical properties of NDCDs were studied by ultraviolet visible (UV–Vis), and fluorescence spectroscopy techniques. Further, the electrocatalytic hydrogen evolution reaction (HER) performance of n-Pd@NDCDs was evaluated by linear sweep voltammetry (LSV), Tafel, and electrochemical impedance spectroscopy (EIS) measurements in 0.5 M aqueous H₂SO₄. The onset potential of n-Pd@NDCDs was about −0.195 V_RHE, which was lower than NDCDS (−0.392 V_RHE) and bare glassy carbon (−0.603 V_RHE). The calculated Tafel slope values of n-Pd@NDCDs were 135 and 141.8 mV/dec, from the voltammetric and EIS methods, respectively. Moreover, the n-Pd@NDCDs exhibited small overpotential of 0.291 V to attain a current density of 10 mA/cm². The EIS studies revealed that the HER charge transfer resistance was dropped from 84.3 to 18.3 Ω/cm² while increasing of potential, which revealed good conductivity and electrocatalytic activity of n-Pd@NDCDs. Thus the present work vouched for the candidature of n-Pd@NDCDs as an effective electrocatalyst for the HER in acidic medium.     

Facile one-step in-situ encapsulation of non-noble metal Co2P nanoparticles embedded into B,N, P tri-doped carbon nanotubes for efficient hydrogen evolution reaction

Developing high performance, good stability and noble-metal-free electrocatalysts for renewable hydrogen evolution reaction (HER) remain a substantial challenge. Herein, we introduce a novel facile one-step in-situ strategy through pyrolysis for the synthesis of Co₂P nanoparticles encapsulated Boron, Nitrogen, and Phosphorous tri-doped carbon nanotubes (Co₂P/BNP-CNTs). The synergetic effect between Co₂P nanoparticles and heteroatom doped CNTs contributes to the remarkable HER performance. The Co₂P/BNP-CNT-900 electrocatalyst shows a low overpotential of 133 mV at a current density of 10 mA cm⁻² and a small Tafel slope of 90 mV dec⁻¹ in 0.1 M KOH media. More importantly, the Co₂P/BNP-CNT-900 electrocatalyst exhibits superior long-term stability in alkaline solution at −0.25 V versus Reversible Hydrogen Electrode (RHE) for 15 h and up to 1000 cycles with negligible performance loss. Overall, our works suggest a one-pot facile synthesis strategy for rational designing high-performance electrocatalysts with enhanced HER performance.     

Copper-N-SiO2 nanoparticles catalyst for hydrogen evolution reaction

Herein, we report the Cu(0)-based nanoparticles film generated by in situ electrochemical reductions of Cu(II) ions modified silica exhibits a high activity and durable HER catalyst in acid solution. Copper ions were attached to silica surface using chemical modification with propyl ethylene diamine (PEDA) linker followed by treating with copper sulfate solution to form Cu(II)-PEDA/silica complex. Copper nanoparticles then were obtained by electrochemical reduction of the silica immobilized Cu(II) ions in sulfuric acid solution. The physicochemical properties of the resulted from copper nanoparticles incorporated silica were investigated and analyzed by Energy Dispersive x-ray Spectroscopy (EDS), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction XRD, X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM). The electrochemical characterizations confirm that the Cu(0) nanoparticles supported on silica substrate combining both high activity and stability for hydrogen evolution reaction with overpotential(η), of 200 mV and Tafel slope of 67 mV/dec could serve as Cu-based electrocatalysts in practical applications for hydrogen production in 0.5 M of H₂SO₄ solution.The catalyst exhibited respectable stability and steadily produced hydrogen at several potentials. The catalyst has the perspective to expressively lower the cost of manufacturing hydrogen fuel, thus helping to spread the use of hydrogen fuel which does not harm the environment.     

Metal-organic frameworks derived N,S,O-doped carbon sheets coated CoP/Co3S4 hybrids for enhanced electrocatalytic hydrogen evolution reaction

Evidence shows that embedding metal-based hybrid into carbon matrix is an up-and-coming method to improve the efficiency and decrease the cost of electrocatalysts. Herein, by using a metal-organic framework (MOF) with 4,4-bipyridine and 2,5-thiophenedicarboxylic acid as a precursor, a CoP/Co₃S₄ hybrid embedded into N, S, O-doped carbon sheets (CoP/Co₃S₄@NSOC) was constructed through pyrolysis and phosphorization processes. The lamellar morphology, hetero-atom doping, and graphite carbon were favorable for fast electron and mass transfer. Moreover, the strong intrinsic activities of CoP and Co₃S₄ promoted electrocatalytic performance. In the electrochemical experiments, CoP/Co₃S₄@NSOC showed the lowest overpotential of 132 mV@10 mA cm^?2 for hydrogen evolution reaction (HER) among all the precursors. In addition, the electrocatalytic activity and structure of CoP/Co₃S₄@NSOC exhibited long-term stability over 60 h. The present work provides a feasible strategy for the construction of robust MOF-derived electrocatalysts.     

Facile synthesis of tubular CoP as a high efficient electrocatalyst for pH-universal hydrogen evolution

A facile three-step approach for tubular CoP preparation and its catalytic activity for HER and OER are reported. The CoP microtubes show superior HER performance in a wide pH range with low overpotentials of 91, 101 and 113 mV at 10 mA cm^?2 in 0.5 M H₂SO₄, 1 M KOH and 1 M PBS, respectively. Additionally, it also depicts superior OER performance with an overpotential of 300 mV at 10 mA cm^?2, which is lower than reported precious metal oxides. The improved electrocatalytic performance of tubular CoP is likely attributed to the porous tube-like structural features, which not only afford rich exposed active sites, but also accelerate the charge or mass transfer efficiency, and thus efficiently promote the HER performance. The synthesis of tubular CoP confirms the importance of morphology features and provides a new insight to rationally design and synthesize highly effective non-noble metal phosphide-based pH-universal electrocatalysts for HER.     

Ultrafine and highly-dispersed bimetal Ni2P/Co2P encapsulated by hollow N-doped carbon nanospheres for efficient hydrogen evolution

Ultrafine Ni₂P/Co₂P nanoparticles encapsulated in hollow porous N-doped carbon nanospheres are synthesized through a facile two-step access. Firstly, metallic Ni and Co coated by hollow N-doped spheres as precursors are obtained through a high temperature calcination route of organic polymer and inorganic Ni and Co salts. Then bimetal Ni₂P/Co₂P supported on N-doped carbon nanospheres are acquired by a facile phosphorization process. It is worth to note that aniline-pyrrole polymer can prevent fast growth and severe aggregation of Ni₂P/Co₂P, which implies more exposed active sites. Moreover, the calcination of hollow polymer spheres lead to the formation of ultrathin NC shell on the surface of Ni₂P/Co₂P hybrids, which can tune electronic structures, improve the conductivity and protect active sites from corrosion in harsh conditions. When used as HER catalyst, it displays remarkable catalytic activity in both acidic and alkaline solutions, which needs an onset potential of only 164 mV and 168 mV, respectively. Therefore, this work may propose a new strategy to design unique inorganic-organic heterostructures to combine ultrafine metal phosphides with porous carbon for efficient HER.     

Cobalt doping VS2 on nickel foam as a high efficient electrocatalyst for hydrogen evolution reaction

The development of non-precious metal catalysts with abundant reserves, low prices and good performance for HER is desired. In this work, rodlike Co doping VS₂ arrays on nickel foam (NF) (Co-VS₂/NF) were fabricated by a simple one-step solvothermal method. Structure characterization indicated that Co doping reduced the size of rodlike Co-VS₂ and meanwhile can modulate its electronic structure, which is beneficial for the enhancement of HER performance. The optimal Co-VS₂/NF-2 reveals a low overpotential of 164.5 mV at ?10 mA cm^?2, small Tafel slope of 52.2 mV dec^?1 and excellent long-term stability after 2000 cycles in 1 M KOH.     

MoS2||CoP heterostructure loaded on N,P-doped carbon as an efficient trifunctional catalyst for oxygen reduction,oxygen evolution,and hydrogen evolution reaction

Exploring multifunctional electrocatalysts is crucial for the development of energy conversion and storage equipments, such as fuel cells, water splitting devices and zinc-air batteries. Herein, we provide a rational design whereby the cobalt phosphide particles are introduced into molybdenum sulfide nanosheets to form a heterostructure (MoS₂||CoP) through the ultrasonic method and calcination. Subsequently, N, P-doped carbon (NPC) is obtained synchronously. The as-prepared MoS₂||CoP/NPC demonstrates highly effective multifunctional catalytic performance for oxygen evolution and hydrogen evolution reaction at lower overpotential, as well as oxygen reduction reaction at high half-wave potential. What this reveals is higher power density and superior stability in zinc-air battery. The excellent electrocatalytic activity of MoS₂||CoP/NPC may be attributed to the presence of the MoS₂||CoP heterostructure, as well as N, P-doped carbon coupled with a high percentage of pyridinic-N. This work proposes a novel and facile strategy to prepare the heterostructure compound and serves as a good reference for constructing efficient and low-cost electrocatalysts.     

N,P-co-doped carbon coupled with CoP as superior electrocatalysts for hydrogen evolution reaction and overall water splitting

To achieve high activity and stability for both hydrogen and oxygen evolution reactions through the non-precious-metal based electrocatalysts is still facing the great challenge. Herein, we demonstrate a facile strategy to prepare CoP nanoparticles (NPs) loaded on N, P dual-doped carbon (NPC) electrocatalysts with high concentration N and P dopants through a pyrolysis-deposition-phosphidation process. The great bifunctional electrocatalytic activity for both HER (the overpotential of 98 mV and 86 mV at 10 mA cm⁻² in both 0.5 M H₂SO₄ and 1 M KOH electrolytes, respectively) and OER (the overpotential of 300 mV at 10  mA cm⁻² in 1 M KOH electrolyte) were achieved. When CoP@NPC hybrid was used as two electrodes in the 1 M KOH electrolyte system for overall water splitting, the needed cell potential for achieving the current density of 10 mA cm⁻² is 1.6 V, and it also showed superior stability for HER and OER after 10 h’ test with almost negligible decay. Experimental results revealed that the P atoms in CoP were the active sites for HER and the CoP@NPC hybrid showed excellent bifunctional electrocatalytic properties due to the synergistic effects between the high catalytic activity of CoP NPs and NPC, in which the doping of N and P in carbon led to a stronger polarization between Co and P in CoP, promoting the charge transfer from Co to P in CoP, enhancing the catalytic activity of P sites and Co sites in CoP for HER and OER, respectively. Specifically, the improvements could result from the changed charge state, the increased active specific surface area, and the facilitated reaction kinetics by N, P co-doping and admixture. This work provides a high-efficient, low-cost and stable electrocatalyst for overall water splitting, and throws light on rational designing high performance electrocatalysts.     

Amorphous CoFeB on nickel foam as a high efficient electrocatalyst for hydrogen evolution reaction

The development of high-performance, low cost and earth abundant catalysts for hydrogen evolution reaction (HER) is desired. This work presents amorphous CoFeB supported on nickel foam (NF), prepared by a facial chemical reduction method, as an active catalyst for HER in alkaline solution. Structure characterization indicated that with the incorporation of Fe atom, CoFeB catalysts exhibit similar petal-like granular morphology as CoB. The optimal CoFeB/NF-0.15 catalyst exhibits Brunauer-Emmett-Teller (BET) surface area of 27.4 m² g^?1, nearly two times larger than 13.2 m² g^?1 for CoB, suggesting higher specific surface area. CoFeB/NF-0.15 catalyst shows excellent HER performance and reaches ?10 mA cm^?2 at overpotential of 35 mV in alkaline solution, and Tafel slope of 84.7 mV dec^?1, indicative of Volmer-Heyrovsky reaction mechanism. The synergistic effect among Fe, Co and B atoms and the more exposed active sites as well as faster electron transfer kinetics collectively contributed to the improved intrinsic activity of CoFeB for HER. Moreover, CoFeB/NF-0.15 exhibits good stability for over 16 h.     

Cobalt nanoparticles encapsulated in nitrogen-rich carbonitride nanotubes for efficient and stable hydrogen evolution reaction at all pH values

Developing non-precious and high-efficiency Pt free electrocatalysts for the hydrogen evolution reaction (HER) in both acid and base remained as a significant challenge. Herein, a novel Co nanoparticles encapsulated in nitrogen-rich carbonitride (Co@Co–N–C) electrocatalyst was fabricated via a facile approach of melamine polymerization and Co²⁺ in situ deposition and reduction. The optimized Co@Co–N–C catalyst demonstrates outstanding catalytic activity for HER in a wide range pH values. In particular, it shows ultralow onset potentials of 62 mV and 46 mV and overpotentials of 178 mV and 157 mV to achieve current density of 10 mA cm^?2 in acidic and alkaline media, respectively. Moreover, it presents outstanding electrochemical durability without degradation at all pH values. Such highly efficient electrocatalytic performance is mainly attributed to the maximum of synergistic effects between uniform dispersed Co nanoparticles and N-rich carbonitride nanotubes.     

Porous N-doped Mo2C@C nanoparticles for high-performance hydrogen evolution reaction

Exploration for an earth-rich and competent electrocatalyst for the hydrogen evolution reaction (HER) is a significant and challenging approach to confronting the resources shortage and environmental crisis. Porous N-doped Mo₂C@C (N-Mo₂C@C) nanoparticles self-encapsulated in nanospheres are presented as a high-performing HER electrocatalyst fabricated through a one-pot solvothermal method followed by hydrogen calcination. Structural analyses show that acetamide can regulate the size of the nanospheres, provide a N source for doping and form porous structures composed of Mo₂C, which suggests the exposure of extensive active sites as well as the contact and diffusion among the medium, electrodes, and gas. Theoretical calculations show that the N doping can enhance the activity of the Mo-C bond, reduce the energy of capturing hydrogen intermediates, and increase the catalytic conductivity. This work offers a simple and promising strategy to understand the catalytic mechanism required to optimize the activity of Mo-based electrocatalysts via N doping.     

Hydrogen evolution reaction on glassy carbon electrode modified with titanyl phthalocyanines

In this work, electrocatalytic activities of titanyl phthalocyanines coated on the glassy carbon working electrode(GCE) were investigated for hydrogen evolution reaction by cyclic voltammetry and chronoamperometry. Multi-electron, reversible, diffusion controlled, and metal-based reduction properties of the complexes show possible application as an electrocatalyst for hydrogen evolution reaction in aqueous solution. The complexes are easily electrodeposited on the glassy carbon electrode during the repetitive cycles, a very useful feature for application in fabrication of thin films. It is shown that especially catecholato-octakis(2-dimethylaminoethylsulfanyl phthalocyaninato) titanium(IV) and octakis(2-dimethylaminoethylsulfanyl phthalocyaninato) titanium(IV) derivatives electrodeposited on GCE have significant catalytic activities towards hydrogen evolution reaction. Electrocatalytic activities change irregularly with the pH of the solution. Moreover, the catalytic activity of the complexes enhanced significantly, when the complexes were incorporated into the Nafion polymeric matrix. Octakis(2-dimethylaminoethylsulfanyl phthalocyaninato) titanium(IV) incorporated into Nafion polymeric matrix decreases the overpotential of hydrogen evolution reaction on the glassy carbon electrode upto 0.32 V with augmenting hydrogen discharge current.     

Facile and large-scale preparation of Co/Ni-MoO2 composite as high-performance electrocatalyst for hydrogen evolution reaction

Facile fabrication of high-performance catalyst based on low-cost metals for sustainable hydrogen evolution is still a matter of cardinal significance. However, synthetic approaches for electrocatalyst are usually complicated and the yields are often low. Herein, we report a one-step simple method for the large-scale synthesis of Co/Ni-MoO₂ composite as efficient and stable hydrogen evolution reaction (HER) electrocatalyst to drive 10 mA cm^?2 current density with a low overpotential of 103 mV in basic media. Co-MoO₂ and Ni-MoO₂ were also prepared using this method with overpotential of 137 and 130 mV, respectively, to gain the same current density. These results indicate that this facile synthesis approach is of great practical importance as it can be easily used for large-scale preparation of electrocatalysts in industry.     

Electrocatalytic hydrogen evolution on iron-cobalt nanoparticles encapsulated in nitrogenated carbon nanotube

Using low-cost nonprecious metals to replace Pt as hydrogen evolution reaction (HER) electrocatalyst is promising, but still limited by their efficiency and stability. Herein, with low-cost dicyandiamide and metal salts as precursor, FeCo alloy nanoparticles encapsulated in nitrogenated carbon nanotubes (FeCo-NCNTs) were facially synthesized as efficient HER electrocatalyst. Addition of iron as second element, though not facilitating the formation of carbon nanotube, was utilized to improve the physicochemical properties of metals. Via optimizing the atomic molar ratios of Fe/Co nanoparticles, the optimal Fe_0.4Co_0.6-NCNTs with thin carbon shell (c.a. 5–10 layer) and equally distribution of embedded alloy nanoparticles was found with outstanding HER activity. To achieve a current density of 10 mA cm⁻², only overpotential of 50 mV, 157 mV and 202 mV were needed in acidic (0.5 M H₂SO₄), alkaline (1 M KOH), and neutral solutions. Its higher electrochemically active surface areas and lower electron transfer resistance may contribute to the excellent electrocatalytic HER. Furthermore, the illustrated current density slightly changed over 20 h, suggesting excellent stability. Hence, the present method provides cost-effective, high efficiency, and stable materials in developing the sustainable energy conversion systems.     

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.     

Nano P zeolite modified with Au/Cu bimetallic nanoparticles for enhanced hydrogen evolution reaction

In the present study, the excellent catalytic performance of Au/Cu bimetallic nanoparticles based on nano P zeolite modified carbon paste electrode (Au/Cu-NPZ-CPE) as one of the most promising electrocatalyst toward hydrogen production is introduced. Herein, nano P zeolite is synthesized by using agriculture residues, stem sweep ash with purity approximately 80.205 wt% of SiO₂ which provides attractive economically silica source for the preparation of inexpensive zeolite. For the preparation of Au/Cu-NPZ-CPE, ion exchange protocol followed by galvanic replacement reaction was employed to result Au/Cu embedded zeolite framework. By evaluating the electrocatalytic activity of proposed catalyst with linear sweep voltammetry and Tafel polarization, a low overpotential of 100 mV and high exchange current density (2.51 mA cm⁻²) are demonstrated which compares favorably to most previously reported electrocatalysts for hydrogen evolution reaction. Owing to the inherent porosity of synthesized nano P zeolite, it successfully prevents the aggregation of bimetallic nanoparticles which promotes the hydrogen evolution reaction. Particularly, low Tafel slope for offered catalyst (33 mV dec⁻¹) demonstrates the acceleration of hydrogen evolution reaction kinetics owing to the increase in the number of accessible active sites. Tafel slope of Au/Cu-NPZ-CPE is 3, 5, 6, 6.5 and 7 times lower than that for Au-NPZ-CPE, Cu-NPZ-CPE, Au/Cu-CPE, NPZ-CPE and CPE, respectively, which shows the best electrocatalytic activity among other modified carbon paste electrodes. Furthermore, the corresponding long term stability test by chronoamperometry method indicates that the current density reaches to nearly 91% of its primary value (after 5500 s) which provides the favorable practical demands of the catalyst in hydrogen production.