Defect-induced FexNi1-xSe2 nanoparticles based electrocatalysts towards enhanced hydrogen and oxygen evolution reactions

Transition metal selenides are regarded as promising materials for the production of clean energy through electrocatalytic water splitting. Creation of defects in these metal selenides is one of the prudent strategies to enrich the active sites which in turn enhances the electrocatalytic activity of these materials and makes them viable for broader applications. Herein, defect-induced, iron-doped nickel selenide nanoparticles were prepared for the first time and their electrocatalytic efficacy towards hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) has been demonstrated. Fe_xNi_1-xSe₂ nanoparticles (x = 0.25, 0.50, 0.75) were prepared using a facile hydrothermal method, in which defects were induced by annealing at 300 °C to obtain DI-Fe_xNi_1-xSe₂. The structural and morphological investigations confirmed the size reduction and creation of defects after annealing, without any significant change in the crystal structure, which in turn is expected to promote the electrocatalytic activity. Accordingly, among all the materials investigated, DI-Fe_0.25Ni_0.75Se₂ has shown the highest HER activity in 0.5 M H₂SO₄ at a lesser overpotential of 128 mV at 10 mA cm^?2 and the Tafel slope was calculated to be 37.9 mV dec^?1. Interestingly, the same material has displayed high performance towards OER in 1 M KOH with a lesser overpotential at 205 mV and a Tafel slope of 55.5 mV dec^?1. Thus obtained electrocatalytic activity was much better than the reported nickel selenide based electrocatalysts. Further, the DI-Fe_0.25Ni_0.75Se₂ electrocatalyst has demonstrated impressive stability in the acidic and alkaline medium during continuous electrolysis even up to 12 h.     

Tuning of electrocatalytic activity of mixed metal dichalcogenides supported NiMoP coatings for alkaline hydrogen evolution reaction

The mixed metal dichalcogenides combination of WS₂–MoS₂ was coated onto Cu substrate by electroless NiMoP plating technique and the electrocatalytic hydrogen evolution reaction (HER) performance was investigated. The enhanced structural, morphological parameters and boosted electrocatalytic performance of the various metal-metal molar ratio of WS₂–MoS₂ onto NiMoP plate were identified under variable operating conditions and it was successfully evaluated by various characterization techniques. The well-defined crystalline nature, phase, particle size, structure, elemental analysis and surface morphology of prepared coatings were analyzed by FESEM, XRD, AFM and EDS mapping. The electrochemical analysis was performed using open circuit potential (OCP) analysis, chronoamperometry (CA), electrochemical impedance spectroscopy (EIS), Tafel curves, linear sweep voltammetry (LSV), cyclic voltammetry (CV) and polarization studies to find the activity of prepared electrocatalyst towards electrochemical hydrogen evolution reactions. The performance of bare NiMoP and WS₂–MoS₂/NiMoP plates were compared and found that the HER activity of NiMoP can be reinforced by composite incorporation through the synergic effect arises with in the catalytic system, which improves surface roughness and enhances the magnitude of electrocatalyst toward HER. The achievement of enhanced catalytic performance of coatings was authenticate by the kinetic parameters such as decreases in Tafel slope (98 mV dec^?1), enhanced exchange current densities (9.32 × 10^?4 A cm^?2), and a lower overpotential. The consistent performance and durability of the catalyst were also investigated. The enhanced electrocatalytic activity of WS₂–MoS₂/NiMoP coatings increased with respect to the surface-active sites associated with combination of mixed dichalcogenides and the synergic effect arises in between different components present in the coating system. This work envisages the progressive strategies for the economical exploration of a novel WS₂–MoS₂/NiMoP water splitting catalyst used for large scale H₂ generation. The prepared WS₂–MoS₂/NiMoP embedded Cu substrate possess high catalytic activity due to its least overpotential of 101 mV at a benchmark current density of 10 mA cm^?2, which demonstrated the sustainable, efficient and promising electrocatalytic property of prepared catalyst towards HER under alkaline conditions.     

Facile construction of 3D hyperbranched PtRh nanoassemblies: A bifunctional electrocatalyst for hydrogen evolution and polyhydric alcohol oxidation reactions

Development of highly effective and stable electrocatalysts is urgent for various energy conversion applications. Herein, a facile co-reduction approach was developed to fabricate three-dimensional (3D) hyperbranched PtRh nanoassemblies (NAs) under solvothermal conditions, where creatinine and cetyltrimethylammonium chloride (CTAC) were employed as the structure-directing agents. The as-synthesized nanocatalyst exhibited intriguing catalytic characters for hydrogen evolution reduction (HER) with a low overpotential (20 mV) at 10 mA cm⁻² and a small Tafel slope (49.01 mV dec⁻¹). Meanwhile, the catalyst showed remarkably enlarged mass activity (MA: 2.16/2.02 A mg⁻¹) and specific activity (SA: 4.16/3.88 mA cm⁻²) towards ethylene glycol and glycerol oxidation reactions (EGOR and GOR) alternative to commercial Pt black and homemade Pt₃Rh nanodendrites (NDs), PtRh₃ NDs and Pt nanoparticles (NPs). This method offers a feasible platform to fabricate bifunctional, efficient, durable and cost-effective nanocatalysts with finely engineered structures and morphologies for renewable energy devices.     

NiMo/Cu-nanosheets/Ni-foam composite as a high performance electrocatalyst for hydrogen evolution over a wide pH range

We designed and fabricated non-precious and highly efficient electrocatalysts of nickelmolybdenum/copper-nanosheets/nickel-foam composites (NiMo/Cu-NS/NF) by step electrodepositions, combining with chemical oxidation method. The catalysts were charaterized by means of SEM, XRD and XPS spectra. Their electrocatalytic activities were assessed by hydrogen evolution reactions (HER) over a wide pH range, where acidic, neutral and alkaline electrolytes were used, respectively. Benefiting from the unique midlayer Cu nanosheets (NS) architecture and optimum Mo–Ni composition at the surface layer which led to high electronic conductivity and large electrochemically active surface area (ECSA), the NiMo/Cu-NS/NF-2 catalyst displayed superior electrocatalytic activities with low overpotentials of η₁₀ = 43, 86 and 89 mV in 0.5 M H₂SO₄, 1.0 M PBS and 1.0 M KOH electrolyte, respectively. Especially in the acidic condition, it exhibited the best electrocatalytic activity with smaller Tafel slope of 54 mV dec^?1 and higher exchange current density of 1.93 mA cm^?2.     

Synergistic regulation of hydrogen adsorption/desorption via dual interfaces of Cu/Ni/Ni(OH)2 toward efficient hydrogen evolution reaction

Nickel-based catalysts have attracted tremendous attention as alternatives to precious metal-based catalysts for electrocatalytic hydrogen evolution reaction (HER) in virtue of their conspicuous advantages such as abundant reserves and high electrochemical activity. Nevertheless, a great challenge for Ni-based electrocatalyst is that nickel sites possess too strong adsorption for key intermediates H1, which severely suppresses the hydrogen-production activities. Herein, we report a hierarchical architecture Cu/Ni/Ni(OH)₂ consisting of dual interfaces as a high-efficient electrocatalyst for HER. The Cu nanowire backbone could provide geometric spaces for loading plenty of Ni sites and the formed Ni/Cu interface could effectively weakened the adsorption intensity of H1 intermediates on the catalyst surface. Moreover, the H1 adsorption could be further controlled to appropriate states by in-situ formed Ni(OH)₂/Ni interface, which simultaneously promotes water adsorption and activation, thus both Heyrovsky and Volmer steps in HER could be obviously accelerated. Experimental and theoretical results confirm that this interface structure can promote water dissociation and optimize H1 adsorption. Consequently, the Cu/Ni/Ni(OH)₂ electrocatalyst exhibits a low overpotential of 20 mV at 10 mA cm^?2 and an ultralow Tafel slope of 30 mV dec^?1 in 1.0 M KOH, surpassing those of reported transition-metal-based electrocatalysts and even the prevailing commercial Pt/C.     

Fe-doped NiCo2S4 catalyst derived from ZIF – 67 towards efficient hydrogen evolution reaction

The development of economical, efficient and stable non-noble metal catalysts plays a key role in electrocatalytic hydrogen evolution. NiCo₂S₄ has been proved to be an efficient non-noble catalyst, to further improve its electrocatalytic performance is a meaningful work. In this paper, the effects of Fe doping on electrochemical performance of NiCo₂S₄ is investigated. The Fe-doped NiCo₂S₄ catalyst is prepared by a facile solvothermal method with metal-organic-framework (MOF, ZIF-67) as template, and it exhibits an improved hydrogen evolution reaction (HER) performance with an overpotential of 181 mV at 10 mA cm^?2, a Tafel slope of 125 mV dec^?1 compared with that of NiCo₂S₄ (252 mV overpotential and 149 mV dec^?1 Tafel slope). The combination of improved conductivity, mesopores architecture retained with the ZIF-67 template, which result the reduced internal resistance, enhanced charge transportation as well as large electrochemical double-layer capacitance. This work provides an effective and synergistic strategy for fabricating NiCo₂S₄-based catalysts toward electrochemical water splitting.     

Ruthenium-manganese phosphide nanohybrid supported on graphene for efficient hydrogen evolution reaction in acid and alkaline conditions

Transition metal phosphides (TMPs) have been proved to be promising, economical and effective catalysts for hydrogen evolution reaction (HER). Precious metals with transition metals alloying can appropriately adjust the adsorption energy, which is an effective solution for greatly reducing the cost of noble metal catalysts and improving their inherent performance. Herein, a simple method was employed to synthesize MnRuPOGO-500 nano-catalysts with a particle size of about 5 nm, which showed excellent HER performance under both acid and basic media. In acidic solution, the optimal catalyst displayed the overpotential of HER to reach 10 mA cm^?2 with 109 mV, a small Tafel slope of 38.55 mV dec^?1 and long-time durability of 60 h. Especially in alkaline medium, the low overvoltage of 27 mV, a small Tafel slope of 57.35 mV dec^?1 and continuing stability of 48 h were further achieved. Meanwhile, we can find that manganese has negligible HER activity, but the doping of manganese generates a synergistic modulation effect in the MnP–Ru₂P alloy, thereby improving the HER performance of the catalyst. This paper brings a simple scheme and unique insights to the design of transition metals and platinum group metals (PGMs) phosphide alloy electrocatalysts.     

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.     

Extraordinarily high hydrogen-evolution-reaction activity of corrugated graphene nanosheets derived from biomass rice husks

The metal-free carbonaceous catalysts are one of the promising candidates for efficient electrocatalytic hydrogen production. Aiming at demonstrating the high electrocatalytic activity of the hydrogen evolution reaction (HER), we synthesized the biomass rice husk-derived corrugated graphene (RH-CG) nanosheets via the KOH activation. The 700 °C-activated RH-CG nanosheets exhibited the large specific surface area as well as the high electrical conductivity. When using the RH-CG nanosheets as a HER electrocatalyst in 0.5 M H₂SO₄, the excellent HER activities with a small overpotential (9 mV at 10 mA/cm²) and a small Tafel slope (31 mV/dec) were achieved. The results provide a new strategy for materializing the superb biomass-derived electrocatalyst for highly efficient hydrogen production.     

Fabrication of phosphorus-mediated MoS2 nanosheets on carbon cloth for enhanced hydrogen evolution reaction

Molybdenum sulfide (MoS₂) as a graphene-like sheet material has attracted wide attention owing to the potential for hydrogen evolution reaction (HER). However, the large-scale application of MoS₂ is still difficult due to the inherent poor conductivity and insufficient active edge sites. Herein, we develop a simple method to grow P-doped MoS₂ nanosheets on carbon cloth for high efficiency HER. The 2D carbon cloth can prevent the stacking of MoS₂ nanosheets and improve the conductivity with the doping of P atoms. As a result, the P–MoS₂/CC-300 shows the excellent electrocatalytic activity with an overpotential of 81 mV at 10 mA cm^?2 and the lower Tafel slope of 98 mV/dec. Furthermore, it also shows the good electrocatalytic durability for 15 h. This work provides an opportunity for the design of excellent and robust MoS₂-based catalyst via structural engineering and doping method.     

Mo-incorporated three-dimensional hierarchical ternary nickel-cobalt-molybdenum layer double hydroxide for high-efficiency water splitting

Flowers-like 3D hierarchical ternary NiCoMo-layered double hydroxide (NiCoMo-LDH) spheres have been fabricated in substrate-free route via a one-pot hydrothermal method and utilized as efficient electrocatalysts for the OER and HER. The well-structured 3D hierarchical flowers were composed of numerous two-dimensional nanosheets, which inherently possess considerable electrochemical active sites, thereby enhancing catalytic activity. NiMo and CoMo binary LDHs, with similar morphology, were also prepared to illustrate the efficiency of the ternary LDH. The results indicate higher electrocatalytic activity for the ternary LDH as compared to binary LDHs under alkaline conditions. The NiCoMo-LDH required an overpotential as low as 202 and 93 mV to deliver a constant anodic and cathodic current density of 10 mA cm^?2 for the OER and HER, respectively. Furthermore, the NiCoMo-LDH exhibited remarkable HER activity, affording a low overpotential of 198 mV at a current density of ?100 mA cm^?2. Moreover, it could offer a stable current density of 10 mA cm^?2 for overall water splitting at 1.62 V in 1 M KOH with long-term stability for 20 h. The double-layer capacitance (C_dl) value indicated that the NiCoMo-LDH significantly influenced interface conductivity and the electrochemical active surface area. The ternary NiCoMo-LDH electrode yielded low Tafel slope values of 54 and 51 mVdec^?1 for the OER and HER. Owing to the efficient incorporation of Ni, Co, and Mo in a layered structure, synergetic effect, and high electrochemical surface area, the NiCoMo-LDH exhibited remarkable electrocatalytic activity. Such eco-friendly ternary LDHs can be used in rechargeable metal–air batteries for industrial applications.     

Boosting electrochemical hydrogen evolution activity of MoS2 nanosheets via facile decoration of Au overlayer

--Owing to its unique physicochemical properties, two-dimensional (2D) layered MoS₂ has been proposed as a potential catalyst for efficient hydrogen evolution reaction (HER). However, their large-scale application is still hindered due to limited active sites, poor conductivity, and restacking during synthesis. Herein, we report a one-step hydrothermal route to grow MoS₂ nanosheets on molybdenum (Mo) foil substrate followed by Au decoration as an active cocatalyst to enhance the HER performance of MoS₂ nanosheets. A facile, quick, and controlled decoration of stable Au overlayer with different mass loadings was performed using a sputtering Au coating unit for different deposition times (10s, 30s, and 50s), thus paving the way for producing efficient and inexpensive HER electrocatalysts. Electrochemical studies of different Au–MoS₂/Mo hybrids demonstrate that the optimized Au–MoS₂/Mo-30s sample exhibits ultralow onset potential (52 ± 2 mV vs. RHE), small overpotentials of 136 ± 6 and 318 ± 3 mV (vs. RHE) at current densities of 10 and 100 mA cm^?2, a small Tafel slope (46.23 ± 6 mV/dec), along with an outstanding electrochemical stability over a couple of days. Presence of metallic 1T-phase of MoS₂, as well as the synergistic effect between MoS₂ and Au, result in enhanced electrical conductivity, high density of active sites, large electrochemically accessible surface area, and fast charge transfer at the catalyst-electrolyte interface for boosting HER activity of the hybrid catalyst.     

Metal-organic framework derived ellipse-like NiS2 nanocatalyst for stable electrochemical hydrogen generation in alkaline electrolyte

The development of non-precious and high-efficient electrocatalysts to enhance the activity and stability in alkaline media is impending for massive hydrogen and oxygen production. In this study, NiS₂ nanoparticles array with ellipse-like topography was fabricated via simple hydrothermal and sulfurization treatment. The NiS₂-400 featured with the unique loose stacking topographic architecture contributes to more exposed active sites, the smaller contact resistance between electrode/electrolyte, faster ion diffusion and electron transfer. As a result, NiS₂-400 electrode requires only overpotentials of 116 and 178 mV to drive current densities of 10 and 50 mA cm^?2 in 1.0 M KOH towards the hydrogen evolution reaction (HER), coupled with a Tafel slope of 93.0 mV dec^?1. Moreover, the resultant NiS₂-400 nanoparticles exhibit excellent electrochemical stability for more than 50 h. In addition, the density functional theory (DFT) calculation further confirms that the (200) facet acts as the predominant active site, contributing to the enhanced HER performance.     

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.     

Palladium-coated polyaniline nanofiber electrode as an efficient electrocatalyst for hydrogen evolution reaction

In this study, polyaniline (PANI) with abundant protonated regions was used for the first time as a palladium (Pd) support for enhanced performance in hydrogen evolution reaction (HER). For this purpose, the hierarchical Pd@PANI nanofiber electrode was easily synthesized by electrochemical polymerization of aniline on Au followed by potential-controlled electrochemical deposition of Pd nanoclusters on the PANI. The reported catalyst was characterized by X-ray diffraction, X-ray photoelectron spectroscopy, and field-emission scanning electron microscopy. Linear sweep voltammetry analysis was performed to evaluate the HER performance. Ion transfer behavior was investigated using electrochemical impedance spectroscopy analysis. The electrochemical tests show that the Pd@PANI/Au electrode has a low overpotential of ～60 mV at 10 mA cm^?2 and a small Tafel slope of 35 mV dec^?1 for HER in acidic media, with high catalytic activity and stability. These features will make the Pd@PANI/Au a promising candidate as a high-performance electrocatalyst for HER 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.     

Synthesis of Pt nano catalyst in the presence of carbon monoxide: Superior activity towards hydrogen evolution reaction

The effect of carbon monoxide (CO) on the reduction of Pt ion to metallic Pt is studied. The modified GC electrode with platinum metal synthesized in the presence of CO shows excellent activity for hydrogen evolution reaction (HER). Despite the decrease in the loading of platinum (4.5 × 10⁻⁴ mg cm⁻²) a substantial increase in its electrocatalytic activity towards HER is observed in a sulfuric acid environment. The observed electrocatalytic activity is comparable to available commercial catalysts like Pt/C. Tafel slope was obtained to be 34 mV.dec^−1, and the overpotential was acquired to be 31 mV at the mass activity of 10 mA mg⁻¹ were observed which was very close to kinetic parameters of Pt/C catalyst.     

N-doped graphene supported W2C/WC as efficient electrocatalyst for hydrogen evolution reaction

Tungsten carbides (W₂C and WC) materials, as promising non-precious electrocatalysts, possess highly efficient activity for HER. Herein, N-doped graphene supported tungsten carbide (N–W₂C/WC) nanocomposite is synthesized by spray drying process followed with a two-step pyrolysis treatment, which exhibits a remarkable hydrogen evolution reaction (HER) activity and excellent stability in acidic solution and alkaline solution. N–W₂C/WC displays low overpotentials of 166 mV and 125 mV to achieve a current density of 10 mA cm^?2 and small Tafel slopes of 60.97 and 62.66 mV dec^?1 in 0.5 M H₂SO₄ and 1.0 M KOH, respectively. After 1000 cycles, the electrocatalytic activity of N–W₂C/WC is almost no change in acidic media but slightly decreases in alkaline media. This work might provide a new way to explore high comprehensive performance tungsten-based electrocatalyst for HER.     

Structure and electrocatalytic hydrogen evolution performance of Mo2C thin films prepared by magnetron sputtering

Mo₂C, which has a unique electronic structure similar to the electronic structure of Pt, is considered as the material with the greatest potential to replace Pt as a catalyst for the electrocatalytic hydrogen evolution reaction (HER). However, Mo₂C thin films have not attracted enough attention in the field of electrocatalysis. This work proposes a method for preparing Mo₂C thin films as a catalyst for electrocatalytic HER through radiofrequency magnetron sputtering. The HER activity of the Mo₂C thin film in acidic and alkaline media is studied by changing the deposition power of the Mo₂C target and doping Ni for structural modification. Results show that increasing the deposition power of Mo₂C can significantly enhance the HER activity of the films in acidic and alkaline media, and metal Ni doping can further enhance the HER activity of the Mo₂C films. In an alkaline environment at a current density of 10 mA cm⁻², the films demonstrate an overpotential of as low as 163 mV with a Tafel slope of 107 mV·dec⁻¹. In acidic media, the films present the corresponding overpotential of 201 mV and a Tafel slope of as low as 96 mV·dec⁻¹. Moreover, the Ni-doped Mo₂C films have excellent HER stability. The synergy between doped Ni and Mo vacancies optimizes the strength of the Mo–H bond and the adsorption and desorption equilibrium of active H, thus enhancing HER kinetics. This work guides the possible structural design of Mo₂C thin films for electrocatalytic HER.     

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.