Catalysts For Water Splitting Research Articles

Heterogeneous interface engineering of CoPSe and FePSe3 on open frameworks for boosting highly efficient overall water splitting

Enhancing intrinsic activity of nanostructured heterogeneous catalysts is an effective strategy for improving electrocatalytic performance for hydrogen/oxygen evolution reactions (HER/OER), but it remains challenging. Here, phosphorus (P) and selenium (Se) atoms are incorporated into an open Co-Fe-based Prussian blue analogues to form a heterostructure consisting of CoPSe and FePSe3 via a one-step pyrolysis strategy. The CoPSe/FePSe3 heterojunction greatly reduces the overpotential for HER (91 mV) or OER (172 mV), which is close to that of Pt/C or much better than that of RuO2, respectively. Co-doping of P and Se non-metallic atoms promotes the reaction kinetics and the exposure of active sites in the framework structure with a large specific surface area. The interactions between CoPSe and FePSe3 can eagerly promote the interfacial electron transfer to enhance HER/OER activities. The carbon skeleton can effectively avoid the fast corrosion/aggregation of the embedded CoPSe/FePSe3 heterojunctions, thereby enhancing the catalytic/structural stability for HER/OER. Importantly, for overall water splitting, the electrolyzer with CoPSe/FePSe3 catalyst only requires an overpotential of 0.35 V to achieve a long-term stability (36 h) at 10 mA cm−2, with Faradaic efficiencies near 100 %. This work sheds a new light on promotion of intrinsic activity of heterostructured catalysts for water splitting.

BaTaO2N and quantum dots-based CuO nanocomposites for HER by solar electrochemical water splitting

Barium tantalum oxynitride (BaTaO2N) has been demonstrated to be an attractive catalyst for photo-electrochemical water splitting, especially oxygen evolution reactions. However, the hydrogen production rates and charge transfer resistances of BTN leave much to be desired from a practical standpoint. In fact, it has never been reported for photocathode applications. On the other hand, CuO has been reported for hydrogen evolution reactions. Given this, here nanocomposites of BaTaO2N and copper oxide quantum dots (CuO QDs), where the latter are digestively ripened, are reported for photoelectrochemical water splitting on a carbon paper substrate. To assess the role of ultra-small quantum dots, composites of commercially available CuO nanoparticles with BaTaO2N were also tested. BaTaO2N and CuO QD nanocomposites performed well and showed a high photocurrent density of 3.1 mA cm−2 at 0 V vs RHE. This was also accompanied by reduced charge transfer resistance (225.4 Ω) due to the high interfacial surface area provided by nanoscopic CuO on BaTaO2N.

Catalytic Water Electrolysis by Co-Cu-W Mixed Metal Oxides: Insights from X-ray Absorption Spectroelectrochemistry.

Mixed metal oxides (MMOs) are a promising class of electrocatalysts for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Despite their importance for sustainable energy schemes, our understanding of relevant reaction pathways, catalytically active sites, and synergistic effects is rather limited. Here, we applied synchrotron-based X-ray absorption spectroscopy (XAS) to explore the evolution of the amorphous Co-Cu-W MMO electrocatalyst, shown previously to be an efficient bifunctional OER and HER catalyst for water splitting. Ex situ XAS measurements provided structural environments and the oxidation state of the metals involved, revealing Co2+ (octahedral), Cu+/2+ (tetrahedral/square-planar), and W6+ (octahedral) centers. Operando XAS investigations, including X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), elucidated the dynamic structural transformations of Co, Cu, and W metal centers during the OER and HER. The experimental results indicate that Co3+ and Cu0 are the active catalytic sites involved in the OER and HER, respectively, while Cu2+ and W6+ play crucial roles as structure stabilizers, suggesting strong synergistic interactions within the Co-Cu-W MMO system. These results, combined with the Tafel slope analysis, revealed that the bottleneck intermediate during the OER is Co3+ hydroperoxide, whose formation is accompanied by changes in the Cu-O bond lengths, pointing to a possible synergistic effect between Co and Cu ions. Our study reveals important structural effects taking place during MMO-driven OER/HER electrocatalysis and provides essential experimental insights into the complex catalytic mechanism of emerging noble-metal-free MMO electrocatalysts for full water splitting.

Stirred-electrodeposition construction of porous Fe-doped NiSe nanoclusters as a bifunctional catalyst for water splitting

The electrodeposition method is commonly used for fabricating water splitting catalysts. Traditional methods assume a static precursor solution, ignoring the effects of solution dynamics. We theorized that stirring the solution during electrodeposition could improve mass transfer and current distribution, thereby enhancing electrochemical kinetics and nucleation. Consequently, we developed a novel electrodeposition technique to synthesize Fe-doped NiSe, an effective catalyst for alkaline water hydrolysis, demonstrating exceptional performance and stability. This catalyst notably decreases the overpotentials for OER and HER to 185/266 mV and 101/271 mV at 10 and 300 mA cm−2, respectively. At the same time, the overall water splitting system comprising this catalyst requires only a low potential of 1.48 V to stably catalyze water splitting for over 60 hours. Electrochemical tests indicate that stirred deposition endows the catalyst with a larger electrochemically active area. In-situ Raman spectroscopy reveals NiOOH as an active phase, and Fe doping facilitates NiOOH formation at lower overpotentials, enhancing OER performance. First-principles calculations suggest that Fe doping optimizes the rate-determining step, lowers the activation energy for the OER process, and boosts conductivity. This study presents a method to improve OER efficiency in Ni-based catalysts, offering insights into mechanism control.

Vanadium-Doped Heterogeneous Bimetallic Phosphides Derived from Layered Double Hydroxides for Saline Water Splitting.

The development of energy- and time-saving synthetic methods to prepare bifunctional and high stability catalysts are vital for overall water splitting. Here, V-doped nickel-iron hydroxide precursor by etching NiFe foam (NFF) at room temperature with dual chloride solution ("NaCl-VCl3"), is obtained then phosphating to obtain V-Ni2P-FeP/NFF as efficient bifunctional (oxygen/hydrogen exchange reaction, OER/HER) electrocatalysts, denoted as NFF(V, Na)-P. The NFF(V, Na)-P requires only 185 and 117 mV overpotentials to reach 10 mA cm-2 for OER and HER. When used as a catalyst for water splitting in a full cell, it can be stably sustained for more than 1000 h in alkaline brine electrolysis at both current densities of 100 and 500 mA cm-2. In situ Raman analyses and density functional theory (DFT) show that the V-doping-induced surface remodeling generates hydroxyl oxides as the true catalytic active centers, which not only enhances the reaction kinetics, but also reduces the free energy change in the rate-determining step. This work provides a cost-effective substrate self-derivation method to convert commercial NFF into a powerful catalyst for electrolytic brine, offering a unique route to the development of efficient electrocatalysts for saline water splitting.

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

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

Wood-Structured Nanomaterials as Highly Efficient, Self-Standing Electrocatalysts for Water Splitting.

Electrocatalytic water splitting (EWS) driven by renewable energy is widely considered an environmentally friendly and sustainable approach for generating hydrogen (H2), an ideal energy carrier for the future. However, the efficiency and economic viability of large-scale water electrolysis depend on electrocatalysts that can efficiently accelerate the electrochemical reactions taking place at the two electrodes. Wood-derived nanomaterials are well-suited for serving as EWS catalysts because of their hierarchically porous structure with high surface area and low tortuosity, compositional tunability, cost-effectiveness, and self-standing integral electrode configuration. Here, recent advancements in the design and synthesis of wood-structured nanomaterials serving as advanced electrocatalysts for water splitting are summarized. First, the design principles and corresponding strategies toward highly effective wood-structured electrocatalysts (WSECs) are emphasized. Then, a comprehensive overview of current findings on WSECs, encompassing diverse structural designs and functionalities such as supported-metal nanoparticles (NPs), single-atom catalysts (SACs), metal compounds, and heterostructured electrocatalysts based on engineered wood hosts are presented. Subsequently, the application of these WSECs in various aspects of water splitting, including the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), overall water splitting (OWS), and hybrid water electrolysis (HWE) are explored. Finally, the prospects, challenges, and opportunities associated with the broad application of WSECs are briefly discussed. This review aims to provide a comprehensive understanding of the ongoing developments in water-splitting catalysts, along with outlining design principles for the future development of WSECs.

Synthetic Mn3Ce2O5-Cluster Mimicking the Oxygen-Evolving Center in Photosynthesis.

The photosynthetic oxygen-evolving center (OEC) is a unique Mn4CaO5-cluster that catalyzes water splitting into electrons, protons, and dioxygen. Precisely structural and functional mimicking of the OEC is a long-standing challenge and pressingly needed for understanding the structure-function relationship and catalytic mechanism of O-O bond formation. Herein we report two simple and robust artificial Mn3Ce2O5-complexes that display a remarkable structural similarity to the OEC in regarding of the ten-atom core (five metal ions and five oxygen bridges) and the alkyl carboxylate peripheral ligands. This Mn3Ce2O5-cluster can catalyze the water-splitting reaction on the surface of ITO electrode. These results clearly show that cerium can structurally and functionally replace both calcium and manganese in the cluster. Mass spectroscopic measurements demonstrate that the oxide bridges in the cluster are exchangeable and can be rapidly replaced by the isotopic oxygen of H218O in acetonitrile solution, which supports that the oxide bridge(s) may serve as the active site for the formation of O-O bond during the water-splitting reaction. These results would contribute to our understanding of the structure-reactivity relationship of both natural and artificial clusters and shed new light on the development of efficient water-splitting catalysts in artificial photosynthesis.

High-current-density PB@S-NiCo nanorod array catalyst for urea-assisted water splitting

To alleviate severe environmental and energy pressures, urea oxidation reaction (UOR) was frequently studied as an alternative electrochemical hydrogen production anode reaction for its low theoretical voltage. Herein, a series of self-supported UOR catalysts were synthesized on the combination of PB nanoparticles and sulfur doped NiCoCO3(OH)2 nanorod arrays (PB@S-NiCo NRA) on copper foam. By changing the modifying time of S-NiCo NRA precursor in K3[Fe(CN)6] solution, PB@S-NiCo-X (X=10, 60, 120 for reaction time) were obtained. The highly hydrophilic heterostructure array can adjust the interface electronic structure and accelerate the mass transfer process, thereby optimizing the thermal/kinetic dynamics of urea electrolysis hydrogen production. Over the typical PB@S-NiCo-60 catalyst, only 1.48 V (UOR) and 1.83 V (overall urea electrolysis) were required to drive a large current density of 500 mA cm−2, showing excellent electrocatalytic activities of the composite catalysts. Furthermore, PB component in the composite catalyst enhanced the reaction kinetics to achieve good stability at high current densities. This study provides new ideas for durable urea electrolysis-assisted H2 production.

Iron, Tungsten Dual-Doped Nickel Sulfide as Efficient Bifunctional Catalyst for Overall Water Splitting.

Developing low-cost and highly efficient bifunctional catalysts for both the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER) is a challenging problem in electrochemical overall water splitting. Here, iron, tungsten dual-doped nickel sulfide catalyst (Fe/W-Ni3S2) is synthesized on the nickel foam, and it exhibits excellent OER and HER performance. As a result, the water electrolyze based on Fe/W-Ni3S2 bifunctional catalyst illustrates 10mAcm-2 at 1.69V (without iR-compensation) and highly durable overall water splitting over 100h tested under 500mAcm-2. Experimental results and DFT calculations indicate that the synergistic interaction between Fe doping and Ni vacancy induced by W leaching during the in situ oxidation process can maximize exposed OER active sites on the reconstructed NiOOH species for accelerating OER kinetics, while the Fe/W dual-doping optimizes the electronic structure of Fe/W-Ni3S2 and the binding strength of intermediates for boosting HER. This study unlocks the different promoting mechanisms of incorporating Fe and W for boosting the OER and HER activity of Ni3S2 for water splitting, which provides significant guidance for designing high-performance bifunctional catalysts for overall water splitting.

Palladium–ruthenium binary alloy nanosheets as catalyst for electrochemical water splitting

Palladium–ruthenium binary alloy nanosheets as catalyst for electrochemical water splitting

Investigating BiMeVOx compounds as potential photoelectrochemical and electrochemical materials for renewable hydrogen production

In this study, BiMeVOx compounds (where Me: Co, Mo, Ce, Zr) were synthesized and characterized as potential photoelectrochemical materials for solar water splitting, the hydrogen evolution reaction (HER), and oxygen evolution reaction (OER). The analysis confirmed the successful formation of phase BiMeVOx compounds with the desired crystal structure. Among the tested materials, BiCoVOx(800) showed the highest photocurrent density (674 μA cm−2) and HER/OER activity (Tafel slope: HER = 100 mV dec−1 and OER = 75 mV dec−1), followed by BiMoVOx(800), BiCeVOx(800), and BiZrVOx(800). The superior photoelectrochemical performance of BiCoVOx(800) can be attributed to its unique electronic structure and optimized band alignment, which promote efficient charge separation and facilitate the water splitting and hydrogen evolution processes. The findings of this study highlight the promising potential of the synthesized BiMeVOx materials, particularly BiCoVOx, as efficient photoelectrochemical catalysts for water splitting. These results contribute to the advancement of renewable energy technologies and provide valuable insights for the design and development of novel photoactive materials.

Constructing heterogeneous interface between Co3O4 and RuO2 with enhanced electronic regulation for efficient oxygen evolution reaction at large current density

Exploring effective strategies for developing new high-efficiency catalysts for water splitting is essential for advancing hydrogen energy technology. Herein, Co3O4/RuO2 heterojunction interface is construct through ion exchange reaction and pyrolysis. The as-synthesized Co3O4/RuO2-4 exhibits outstanding oxygen evolution reaction (OER) activity at the current density of 100 mA cm−2 with a low overpotential of 276 mV, and remarkable stability (maintaining activity for 60 h at 100 mA cm−2). Experimental results and theoretical calculations reveal that the electrons around the heterogeneous interface transferred from RuO2 to Co3O4, resulting in electron redistribution and optimization of energy barriers for OER intermediates. This unique composite catalyst structure offers a new potential for designing efficient oxygen electrocatalysts at large current density.

Dual Polarization Strategy for Boosting Electron-Hole Separation toward Overall Water Splitting within Ferroelectric β-AIBIIIO2 (BIII = P3+, As3+, Sb3+, and Bi3+ for Lone Pairs).

Ferroelectric materials, leveraging an inherent built-in electric field, are excellent in suppressing electron-hole recombination. However, the reliance solely on bulk polarization remains insufficient in enhancing carriers' separation and migration, limiting their practical application in photocatalytic overall water splitting (POWS). To address this, we incorporated cations with ns2 lone pairs (P3+, As3+, Sb3+, and Bi3+) into ferroelectric semiconductors, successfully constructing 44 β-AIBIIIO2 photocatalysts with dual polarization. Through rigorous first-principles calculations and screenings for stability, band characteristics, and polarization, we identified four promising candidates: β-LiSbO2, β-NaSbO2, β-LiBiO2, and β-TlBiO2. Within these materials, lone pairs induce local polarization in the xy-plane. Additionally, out of the plane, there is robust bulk polarization along the z-direction. This synergistic effect of the combined local and bulk polarization significantly improves the separation efficiency of electron-hole pairs. Explicitly, the electron mobility of the four candidates ranges from 105 to 106 cm2 s-1 V-1, while the hole mobility also increases significantly compared to single-phase polarized materials, up to 106 cm2 s-1 V-1. Notably, β-TlBiO2 is predicted to achieve a solar-to-hydrogen (STH) efficiency of 17.2%. This study not only offers insights for water-splitting catalyst screening but also pioneers a path for electron-hole separation through the dual polarization strategy.

Diamondoid Ni(II) Coordination Polymer as an Electrocatalyst for Hydrogen and Oxygen Evolution Reactions and Overall Water Splitting.

We have successfully synthesized a new Ni(II)-based coordination polymer (CP) [Ni2(cis-1,4-chdc)2(4,4'-bpy)3(H2O)2] (1); (cis-1,4- H2chdc=cis-1,4-cyclohexanedicarboxylic acid and 4,4'-bpy=4,4'-bipyridine) employing slow diffusion method in a single pot technique. The connectivity of Ni(II) ions and bridging cis-1,4-chdc ligand gives rise to a three-dimensional (3D) framework with 2-fold interpenetrated diamondoid topology. Interestingly, the synthesized CP acts as efficient catalyst for electrocatalytic water splitting. The water oxidation activity of compound 1 exhibits Tafel slope equivalent to 361.48 mV.dec-1 for hydrogen evolution reaction (HER) and 353.53 mV.dec-1 for oxygen evolution reaction (OER) in an alkaline medium while almost similar values of Tafel slope for HER and OER equivalent to 287.33 mV.dec-1 and 289.93 mV.dec-1 respectively in acidic medium. Thus, the compound 1 has excellent efficacy in catalyzing HER and OER in acidic as well as alkaline medium, which is ascribed to its distinctive 3D architecture.

Acanthosphere-like bimetallic sulfide Cu9S5/Mo2S3/NF as bifunctional catalyst for water splitting

Reducing the overpotential of water splitting is an important strategy for achieving low-cost and large-scale production of hydrogen (H2) and oxygen (O2). It is shown that bimetallic sulfide combines the advantages of a single component and an ideal structure for efficient electrocatalysis. Hence, an acanthosphere-like bimetallic sulfide electrocatalyst Cu9S5/Mo2S3/NF with high catalytic performance and superior durability was prepared by a simple one-pot method. In the oxygen evolution reaction (OER), the Cu9S5/Mo2S3/NF achieved a Tafel slope of 62.7 mV dec-1, and an overpotential of 224 mV at a current density of 10 mA cm−2. Concomitantly, it also possesses a small overpotential of 96 mV at 10 mA cm−2 and low Tafel slope of 81.6 mV dec-1 at the used of hydrogen evolution reaction (HER) catalyst. Moreover, the two-electrode system Cu9S5/Mo2S3/NF||Cu9S5/Mo2S3/NF single cell requires only 1.55 V to achieve a current density of 10 mA cm−2 in overall water splitting. This work highlights the advantages of bimetallic sulfide combines structural for overpotential of water splitting and provides an idea for modifying the catalytic performance of single metal sulfides and preparing high-performance bimetallic sulfide catalysts.

Rational design of multi-component Fe(OH)3/Ni-NiO heterostructures bifunctional catalyst for electrochemical water splitting

Exploring economic-efficient bifunctional catalysts is critical for the production of green hydrogen through water splitting. Herein, we fabricate a novel hybrid catalyst with three-phase heterojunction (Fe(OH)3/Ni-NiO) via a simple electrodeposition and chemical precipitation method. Benefiting from the desirable amorphous-crystal interfaces, the electronic structure of Ni, NiO and Fe(OH)3 is regulated, which will optimize the adsorption of H intermediates (H*) and also reduce the kinetic barrier for the hydrogen evolution reaction (HER). The optimal Fe(OH)3–3/Ni-NiO/CC shows superior bifunctional activity with low overpotentials of 66 mV for HER and 220 mV for OER at 10 mA cm−2 in alkaline solution, respectively, as well as remarkable durability over a period of 40 h. Besides, Fe(OH)3–3/Ni-NiO/CC requires 1.52 and 1.72 V to deliver 10 and 100 mA cm−2 and shows no obvious increase in current within 40 h toward overall water splitting. Experimental and theoretical results show that the HER process is promoted by the synergistic effect of electronic redistribution between Ni, NiO and Fe(OH)3 due to the construction of three phase crystalline-amorphous heterogeneous interface. Meanwhile, Fe(OH)3 and NiO appeared reconstruction, transforming into FeOOH and NiOOH during OER process, respectively. This work offers a simple synthesis method for designing bifunctional catalysts for water splitting.

A Review of the Structure–Property Relationship of Nickel Phosphides in Hydrogen Production

Hydrogen, one of the most promising forms of new energy sources, due to its high energy density, low emissions, and potential to decarbonize various sectors, has attracted significant research attention. It is known that electrocatalytic hydrogen production is one of the most widely investigated research directions due to its high efficiency in the conversion of electricity to H2 gas. However, given the limited reserves and high cost of precious metals, the search for non-precious metal-based catalysts has been widely explored, for example, transition metal phosphides, oxides, and sulfides. Despite this interest, a detailed survey unveils that the surface and internal structures of the alternative catalysts, including their surface reconstruction, composition, and electronic structure, are poorly studied. As a result, a disconnection in the structure–property relationship severely hinders the rational design of efficient and reliable non-precious metal-based catalysts. In this review, by focusing on Ni5P4, a bifunctional catalyst for water splitting, we systematically summarize the material motifs pertaining to the different synthetic methods, surface characteristics, and hydrolysis properties. It is believed that a cascaded correlation may provide insights toward understanding the fundamental catalytic mechanism and design of robust alternative catalysts for hydrogen production.

Self-assembly of NiFe-LDH@Ni3S2 sub-nanosheets catalyst for overall water splitting

The development of water splitting catalysts for generating high-purity hydrogen in large-scale is still facing challenges in terms of improving efficiency and stability. Herein, Ni3S2-coated NiFe layered double hydroxides sub-nanosheets with a hierarchical heterostructure (NiFe-LDH@Ni3S2) were prepared on nickel foam (NF) by a strategy of continuous hydrothermal synthesis. The introduction of S2− broke the hydrogen bonds between NiFe-LDH layers and separated into sub-nanosheets with a thickness of only about 1 nm, which enlarged the active areas of NiFe-LDH@Ni3S2/NF by a factor of 5.7. The coexisting charge channels Ni-O-Ni and Ni-S-Ni in the material enhanced the electrochemical activity, resulting in the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) overpotentials as low as 179 mV and 116 mV at 10 mA cm−2 in 1.0 M KOH. Moreover, after a 50-hour chronopotentiometry test at 50 mA cm−2, the overpotential for OER and HER decreased only 0.013 V and 0.059 V, respectively. Furthermore, under the conditions of simulating industrial hydrogen production with an electrolyte of 6.0 M KOH and a temperature of 75 °C, after a 140-hour test for durability, the current density decreased only 0.75% at the cell voltage of 1.70 V.

Multiwall carbon nanotubes supported rhenium doped Co3O4 as an efficient electrocatalyst for water oxidation in alkaline medium

The recent trends for the development of efficient and low cost transition metal (TMs) based anode catalysts for water splitting is crucial and important. Even though, research is continuously progressing in different directions to design catalyst; however, catalytic OER (oxygen evolution reaction) activity has remained insufficient. Till now, various transition metal oxides (TMOs) have been used as efficient and cost-effective electrocatalyst for the oxygen evolution reaction. The catalytic performance of TMOs could be enhanced by doping with the metal, which increases the catalyst's charge transfer and electronic conductivity. Decoration of TMOs with the multi-wall carbon nanotube (MWCNT) further improves catalytic activity by providing numerous active sites. Here, Co3O4/MWCNT and Rhenium (Re) doped Co3O4/MWCNT composite were prepared by simple hydrothermal process and used as electrocatalyst for OER in alkaline medium. Different concentrations of Re (0.05 mmol, 0.1 mmol, 0.2 mmol, 0.3 mmol) were doped and it was observed that the electrochemical results of the 0.2 mmol Re doped Co3O4/ MWCNT (R0.2CO) was most efficient electrocatalyst which offers the OER overpotential of 298 mV/dec to attain the 10 mA cm−2 current density, lower Tafel slope (70 mV/dec), higher value of turn over frequency (0.95), lower value of the charge transfer resistance (3.10Ω) and good stability, demonstrating the better OER catalytic activity as compared to un-doped Co3O4/MWCNT (R0.0CO) catalyst. The investigated catalyst R0.2CO is more efficient catalyst than most of the reported similar type of catalysts and offers comparable electrocatalytic activity with benchmark electrocatalyst RuO2.