Oxygen Evolution Reaction Activity Research Articles

Metal Doping Regulates Electrocatalysts Restructuring during Oxygen Evolution Reaction.

High-efficiency and low-cost catalysts for oxygen evolution reaction (OER) are critical for electrochemical water splitting to generate hydrogen, which is a clean fuel for sustainable energy conversion and storage. Among the emerging OER catalysts, transition metal dichalcogenides have exhibited superior activity compared to commercial standards such as RuO2, but inferior stability due to uncontrolled restructuring with OER. In this study, we create bimetallic sulfide catalysts by adapting the atomic ratio of Ni and Co in CoxNi1-xSy electrocatalysts to investigate the intricate restructuring processes. Surface-sensitive X-ray photoelectron spectroscopy and bulk-sensitive X-ray absorption spectroscopy confirmed the favorable restructuring of transition metal sulfide material following OER processes. Our results indicate that a small amount of Ni substitution can reshape the Co local electronic structure, which regulates the restructuring process to optimize the balance between OER activity and stability. This work represents a significant advancement in the development of efficient and noble metal-free OER electrocatalysts through a doping-regulated restructuring approach.

Ligand-Induced Electronic Structure Modulation of Self-Evolved Ni3S2 Nanosheets for the Electrocatalytic Oxygen Evolution Reaction.

Modulating the electronic structure of the electrocatalyst plays a vital role in boosting the electrocatalytic performance of the oxygen evolution reaction (OER). In this work, we introduced a one-step solvothermal method to fabricate 1,1-ferrocene dicarboxylic acid (FcDA)-decorated self-evolved nickel sulfide (Ni3S2) nanosheet arrays on a nickel foam (NF) framework (denoted as FcDA-Ni3S2/NF). Benefiting from the interconnected ultrathin nanosheet architecture, ligand dopants induced and facilitated in situ structural reconstruction, and the FcDA-decorated Ni3S2 (FcDA-Ni3S2/NF) outperformed its singly doped and undoped counterparts in terms of OER activity. The optimized FcDA-Ni3S2/NF self-supported electrode presents a remarkably low overpotential of 268 mV to achieve a current density of 10 mA cm-2 for the OER and demonstrates robust electrochemical stability for 48 h in a 1.0 M KOH electrolyte. More importantly, in situ electrochemical Raman spectroscopy reveals the generation of catalytically active oxyhydroxide species (NiOOH) derived from the surface construction during the OER of pristine FcDA-Ni3S2/NF, contributing significantly to its superior electrocatalytic performance. This study concerns the modulation of electronic structure through ligand engineering and may provide profound insight into the design of cost-efficient OER electrocatalysts.

Magnetic Field Enhanced Cobalt Iridium Alloy Catalyst for Acidic Oxygen Evolution Reaction.

Magnetic field mediated magnetic catalysts provide a powerful pathway for accelerating their sluggish kinetics toward the oxygen evolution reaction (OER) but remain great challenges in acidic media. The key obstacle comes from the production of an ordered magnetic domain catalyst in the harsh acidic OER. In this work, we form an induced local magnetic moment in the metallic Ir catalyst via the significant 3d-5d hybridization by introducing cobalt dopants. Interestingly, CoIr nanoclusters (NCs) exhibit an excellent magnetic field enhanced acidic OER activity, with the lowest overpotential of 220 mV at 10 mA cm-2 and s long-term stability of 120 h under a constant magnetic field (vs 260 mV/20 h without a magnetic field). The turnover frequency reaches 7.4 s-1 at 1.5 V (vs RHE), which is 3.0 times higher than that without magnetization. Density functional theory results show that CoIr NCs have a pronounced spin polarization intensity, which is preferable for OER enhancement.

Self-Assembled Conjugated Coordination Polymer Nanorings: Role of Morphology and Redox Sites for the Alkaline Electrocatalytic Oxygen Evolution Reaction.

Electrocatalytic water splitting provides a sustainable method for storing intermittent energies, such as solar energy and wind, in the form of hydrogen fuel. However, the oxygen evolution reaction (OER), constituting the other half-cell reaction, is often considered the bottleneck in overall water splitting due to its slow kinetics. Therefore, it is crucial to develop efficient, cost-effective, and robust OER catalysts to enhance the water-splitting process. Transition-metal-based coordination polymers (CPs) serve as promising electrocatalysts due to their diverse chemical architectures paired with redox-active metal centers. Despite their potential, the rational use of CPs has faced obstacles including a lack of insights into their catalytic mechanisms, low conductivity, and morphology issues. Consequently, achieving success in this field requires the rational design of ligands and topological networks with the desired electronic structure. This study delves into the design and synthesis of three novel conjugated coordination polymers (CCPs) by leveraging the full conjugation of terpyridine-attached flexible tetraphenylethylene units as electron-rich linkers with various redox-active metal centers [Co(II), Ni(II), and Zn(II)]. The self-assembly process is tuned for each CCP, resulting in two distinct morphologies: nanosheets and nanorings. The electrocatalytic OER performance efficiency is then correlated with factors such as the nanostructure morphology and redox-active metal centers in alkaline electrolytes. Notably, among the three morphologies studied, nanorings for each CCP exhibit a superior OER activity. Co(II)-integrated CCPs demonstrate a higher activity between the redox-active metal centers. Specifically, the Co(II) nanoring morphology displays exceptional catalytic activity for OER, with a lower overpotential of 347 mV at a current density of 10 mA cm-2 and small Tafel slopes of 115 mV dec-1. The long-term durability is demonstrated for at least 24 h at 1.57 V vs RHE during water splitting. This is presumably the first proof that links the importance of nanostructure morphologies to redox-active metal centers in improving the OER activity, and it may have implications for other transdisciplinary energy-related applications.

Metallic Ru─Ru Interaction in Ruthenium Oxide Enabling Durable Proton Exchange Membrane Water Electrolysis.

Developing efficient and robust electrocatalysts toward the oxygen evolution reaction (OER) is critical for proton exchange membrane water electrolysis (PEMWE). RuO2 possesses intrinsically high OER activity, but the concurrent electrochemical dissolution leads to rapid deactivation. Here a unique RuO2 catalyst containing metallic Ru─Ru interactions (m-RuO2) is reported, which maintains stability in practical PEMWE for 100h at 60 °C and 1 A cm-2. Experimental and theoretical investigations suggest that the presence of Ru─Ru interactions significantly increases the energy barrier for the formation of RuO2(OH)2, which is a key intermediate for Ru dissolution, and hence substantially mitigates the electrochemical corrosion of m-RuO2. Meanwhile, the Ru4d band center downshifts, accordingly, ensuring the high OER activity, and the participation of lattice oxygen in the OER is also suppressed at the Ru─Ru sites, further contributing to the enhanced durability. Interestingly, such enhanced stability is also dependent on the size of metallic Ru─Ru cluster, where the energy barrier is further increased for Ru3, but is decreased for Ru5. These results highlight the significance of local coordination structure modulation on the electrochemical stability of RuO2 and open a feasible avenue toward the development of robust OER electrocatalysts for high-performance PEMWE.

Construction of MOF-derived hollow sugar gourd-like Ni-Co-S@NiMoO4•xH2O nanocage arrays for efficient solar-powered overall water splitting

In situ growth of nanoarrays on conductive substrates is an efficient strategy for designing electrocatalysts. However, preparing array with excellent catalytic activities for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) remains a challenge. Here, we construct a novel hollow sugar gourd-like Ni-Co-S@NiMoO4·xH2O/NF nanocage array through MOF derivation strategy for stable solar-driven overall water splitting. Due to the hollow core–shell structure and multi-component advantages, the Ni-Co-S@NiMoO4·xH2O/NF presents high density of active sites and fast charge transfer rate. Therefore, Ni-Co-S@NiMoO4·xH2O/NF exhibits attractive electrocatalytic activity in alkaline electrolytes for HER (90 mV@10 mA cm−2) and OER (208 mV@10 mA cm−2, 245 mV@100 mA cm−2). The corresponding two-electrode electrolytic cell demonstrates small cell voltage (1.515 V @ 10 mA cm−2) and shows durability over 50 h at 10 mA cm−2, exhibiting excellent overall water splitting performance. It is worth noting that the solar-assisted electrolysis cell reaches a high solar-to-hydrogen (STH) conversion rate of 19.4 %. The construction of this unique hollow structure gives a fascinating method for improving the HER and OER performance of transition metal sulfide electrocatalysts.

IrO2 nanoparticles supported on submicrometer-sized TiO2 as an efficient and stable coating for oxygen evolution reaction

The sluggish kinetics of the oxygen evolution reaction (OER) refers to the major contributor to the energy losses in electrowinning of metals. Improving the stability in the long term and activity of the electrocatalyst for OER take on a critical significance in reducing the energy consumption. An efficient and stable OER electrode (named as Ti/SMST/IrO2 electrode) was prepared in this study by supporting IrO2 nanoparticles on the surface of the submicrometer-sized TiO2 (SMST) interlayer. The obtained results indicated that the IrO2 nanoparticles approximately 14 nm in size were supported onto the submicrometer-sized TiO2 particles’ surface and exhibited a cactus-like morphology. The Ti/SMST/IrO2 electrode with the SMST interlayer prepared at 450 °C exhibited the highest electrocatalytic activity in terms of OER for its largest active surface area. This electrode showed an overpotential of 350 mV at a current density of 50 mA cm−2 and displayed a remarkable electrochemical stability of 443 h at a high current density of 2 A cm−2 in H2SO4 solution without significant change in OER activity. The prepared Ti/SMST/IrO2 electrode with high electrocatalytic performance is considered one of the promising electrodes for OER.

Floret assembly of NiCo2O4@Tailored nanostructured carbon support for oxygen evolution reaction in alkaline medium

The oxygen evolution reaction (OER) is a bottleneck in overall water splitting due to the involvement of the four-electron process and requires a high overpotential. This hinders the stability and durability of electrocatalysts over a longer period. Herein, we report flower-like NiCo2O4 decorated on carbon nanostructures synthesized using a one-pot wet chemical method as an OER electrocatalyst in an alkaline medium. The catalytic activities were characterized by various electrochemical measurements including linear sweep voltammetry (LSV), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and turnover frequency (TOF). 90 % NiCo2O4@rGO/f-MWCNT demonstrated a higher OER activity compared to stand-alone NiCo2O4, 90 % NiCo2O4@rGO, 90 % NiCo2O4@f-MWCNT and 80 % NiCo2O4@rGO/f-MWCNT.

Cobalt@Ruthenium Core@Shell nanoparticles embedded within nitrogen-doped carbon nanosheets as reversible oxygen electrocatalysts

Rational design and engineering of cost-effective, high-performance reversible oxygen electrocatalysts for both the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is imperative in advancing the progress of rechargeable metal-air batteries (r-MABs). Herein, nanocomposites based on Co@Ru core@shell nanoparticles embedded within N-doped carbon nanosheets (Co@Ru/CS) are prepared via facile galvanic exchange reactions of RuCl3 with Co/NC and used as an effective oxygen electrocatalyst for rechargeable zinc-air battery (r-ZAB). Electrochemical studies demonstrate a remarkable bifunctional catalytic performance of Co@Ru/CS towards both ORR and OER, featuring a low potential gap (ΔE) of only 0.69 V between the OER potential (E10,OER) at 10 mA cm−2 and half-wave potential (E1/2,ORR) of ORR, which is much lower than that of commercial Pt/C + RuO2 catalysts (0.76 V). Combined studies of experimental characterizations and density functional theory calculations show that the ORR activity arises primarily from the N-doped carbon and CoNx moieties in the composites, whereas RuO2/CoOOH produced at high electrode potentials is responsible for the OER activity. Co@Ru/CS based r-ZAB exhibits an open circuit voltage of 1.447 V, specific capacity of 781 mAh gZn−1, and maximum power density of 115 mW cm−2 at 0.83 V, a performance better than that with commercial Pt/C + RuO2 (1.412 V, 760.56 mAh gZn−1, and 91 mW cm−2). Results from this research underline the substantial impact of structural engineering on optimizing the electrocatalytic activity of nanocomposites for r-MABs.

Fabrication of Ni-Polyaniline/Graphene Oxide Composite Electrode with High Capacitance and Water Splitting Activity.

The Ni-PANI@GO composite electrode was fabricated via cost effective electrodeposition technique. According to the XRD, FTIR, Raman, SEM, and XPS analyses revealed that the nickel doped PANI@GO composite has been fabricated on the surface of the nickel foam. Addition of nickel significantly enhanced interaction between graphene with PANI leading to higher degree of polyaniline doping though imine groups. Electrochemical investigation revelated the significant performance of the Ni-PANI@GO composite electrode, boosting an impressive capacitance of 4480 F/g at 40 A/g, surpassing previous Ni-foam-based binder-free electrodes. Notably, Ni-PANI@GO electrode displayed excellent catalytic activity in both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), generating a considerable volume of the gas bubbles at relatively modest overpotentials of 279 mV and 244 mV respectively. This event allows for the achievement of 20 mA·cm-2 current density. Furthermore, in the laboratory-scale water electrolyzer, a low cell voltage of 1.72 V was achieved, facilitating a water-splitting current density of 20 mA·cm-2. This study underscores the premising potential for the real-world device's application of the versatile Ni-PANI@GO composite electrode.

Intercalated and Surface-Adsorbed Phosphate Anions in NiFe Layered Double-Hydroxide Catalysts Synergistically Enhancing Oxygen Evolution Reaction Activity.

The oxygen evolution reaction (OER), a crucial semireaction in water electrolysis and rechargeable metal-air batteries, is vital for carbon neutrality. Hindered by a slow proton-coupled electron transfer, an efficient catalyst activating the formation of an O-H bond is essential. Here, we proposed a straightforward one-step hydrothermal procedure for fabricating PO43--modified NiFe layered double-hydroxide (NiFe LDH) catalysts and investigated the role of PO43- anions in enhancing OER. Phosphate amounts can efficiently regulate LDH morphology, crystallinity, composition, and electronic configuration. The optimized sample showed a low overpotential of 267 mV at 10 mA cm-2. Density functional theory calculations revealed that intercalated and surface-adsorbed PO43- anions in NiFe LDH reduced the Gibbs free energy in the rate-determining step of *OOH formation, balancing oxygen-containing intermediate adsorption/dissociation and promoting the OER. Intercalated phosphate ions accelerated precatalyst dehydrogenation kinetics, leading to a rapid reconstruction into active NiFe oxyhydroxide species. Surface-adsorbed PO43- interacted favorably with adsorbed *OOH on the active Ni sites, stabilizing *OOH. Overall, the synergistic effects of intercalated and surface-adsorbed PO43- anions significantly contributed to enhanced OER activity. Achieving optimal catalytic activity requires a delicate equilibrium between thermodynamic and kinetic factors by meticulously regulating the quantity of introduced PO43- ions. This endeavor will facilitate a deeper comprehension of the influence of anions in electrocatalysis for OER.

Effect of heat treatment on improving OER activity of NiFeOOH based aerogels: A combined experimental and theoretical study

Enhanced catalytic activity of oxygen evolution reaction (OER) catalysts is necessary to lower the cost of green hydrogen production. This study focuses on the use of a simple strategy of heat treatment to enhance the catalytic activity of NiFeOOH-based aerogels. The study shows that heat treatment of this aerogel at 150°C leads to significant improvement in its catalytic activity, as evident in the staircase voltammetry results. To understand how heat treatment improves the catalytic activity, a DFT+U calculation was carried out on heat-treated and non-heat-treated catalysts. The calculation shows that the overpotential for OER decreases with heat treatment, which is related to the relative stability of the intermediates in heat-treated and non-heat-treated catalysts. Also, it has been found that heat treatment decreases work function, which might improve charge transfer and, thus, catalytic activity. Our calculations are in line with the experimental results that show the release of crystalline water at 150°C which enhances the catalytic activity, and the formation of dense NiFeOx phase at higher temperatures which results in lower activity.

Microflower-like NiFe layered double hydroxide @ g-C3N4 electrocatalysts for enhanced photo-assisted OER and overall water splitting performance

Photo-assisted electrocatalysis has emerged as a cutting-edge area of electrocatalysis in recent times. It relies on the combined influence of electrical and optical energy, offering a novel approach to enhance electrocatalytic efficiency. In this study, we synthesized microflower-like catalysts consisting of NiFe layered double hydroxide and g-C3N4 (known as NiFe-LDH/CN@NF) directly on Ni foam using a one-step hydrothermal technique. Under the irradiation of 300W xenon lamp, the electrocatalytic activities of oxygen evolution reaction (OER) and overall water splitting of NiFe-LDH/CN@NF were significantly enhanced. Under photo-assisted circumstances, the OER overpotential (204mV@10mAcm−2) in KOH electrolyte is 23% lower than in dark conditions; the cell voltage of an electrolytic cell using NiFe-LDH/g-C3N4 as the cathode and anode decreased from 1.65V to 1.58V. According to study on mechanisms, the enhancement in OER can be mainly ascribed to the synergistic impact of photo-driven and electro-driven water oxidation processes. These results validate the broad generalizability of photo-assisted electrocatalysis technology and provide valuable insights into the advanced material design for sustainable energy conversion technologies.

Novel amorphous FeOOH-modified Co9S8 nanosheets with enhanced catalytic activity in oxygen evolution reaction

Efficient oxygen evolution reaction (OER) is vital for water electrolysis and advanced hydrogen energy production. However, the sluggish kinetics of this reaction require significant overpotentials, leading to high energy consumption. Therefore, developing OER electrocatalysts with exceptional performance and long-term durability is crucial for enhancing the energy efficiency and cost-effectiveness of the hydrogen production process. In this research, novel FeOOH/Co9S8 catalysts were prepared through a two-step hydrothermal reaction followed by one-step electrodeposition on nickel foam for an alkaline OER. The as-obtained catalysts possessed abundant non-homogeneous interfaces between FeOOH and Co9S8 nanosheets, conducive to optimized coordination environments of Fe and Co sites by redistributing interfacial charges. This synergy strengthened the chemisorption of oxygenated intermediates, leading to accelerated reaction kinetics, abundant active sites, and enhanced OER performance. The optimized electrocatalyst FeOOH/Co9S8-15 achieved a current density of 10 mA cm−2 at an overpotential of 248 mV and good stability for over 140 h. This study presents a novel approach for producing compelling and durable alkaline dielectric OER electrocatalysts, which will be helpful in the future manufacturing of advanced energy devices.

The acceleration of the active phase transition of NiCoFe hydroxide by Ta doping to achieve Long-Time seawater electrolysis at Ampere-Level current density

Considering the regional distribution of freshwater resources, acquiring hydrogen by seawater electrolysis has lower cost and feasibility. NiCoFe-based materials have been widely studied due to their excellent catalytic oxidation performance in freshwater. However, the large amount of chloride ions in seawater will severely erode the catalytic site and greatly reduce the catalyst's lifetime. In this paper, a two-dimensional nanosheet quaternary metal hydroxide electrode composed of Ni, Co, Fe, and Ta elements was synthesized via a facile one-step hydrothermal method for efficient oxygen evolution reaction (OER) in seawater electrolysis. Structural characterization and in-situ test revealed that the incorporation of Ta not only optimized the electronic structure of the catalyst but also accelerated the formation of the γ-NiOOH phase, making the active phase is protected from being attacked by Cl- ions during the formation process, enhancing its OER activity while achieving extended durability. The catalyst was operated at an ampere-level of 1 A cm-2 for over one month (800 h), and no significant degradation was observed. This work provides a promising strategy for developing cost-effective, efficient, and stable catalysts for challenging applications in seawater electrolysis.

Elucidating the construction and modulation of built-in electric field in the oxygen evolution reaction

The construction of a built-in electric field (BIEF) is considered to be an effective strategy for enhancing catalyst performance due to its critical role in optimizing adsorption of reactants and key intermediates, as well as its positive impact on interface behavior. Herein, a strategy is developed to elucidate the correlation between oxygen evolution reaction activity and the BIEF and its strength by constructing and enhancing the BIEF through incorporating manganese into Co3O4@NiFe-LDH p-n heterojunction. This Co3O4@NiFe-LDH p-n heterojunction generates a BIEF that effectively regulates electronic structure, facilitates rapid electron transfer, induces alterations in the chemical microenvironment, and modulates intermediate adsorption energy. Notably, when hetoroatomic Mn is incorporated into the p-n heterojunction, particularly encapsulated within NiFe-LDH, a more pronounced enhancement for BIEF is observed. Benefiting from this strong BIEF, Co3O4@Mn/NiFe-LDH exhibits excellent OER activity and stability with an overpotential of only 209 mV at 50 mA cm−2, a Tafel slope of 57 mV dec−1, and stable operation for 110 h at approximately 10 mA cm−2. Moreover, density functional theory (DFT) calculations further confirms that the construction and reinforcement of the BIEF can effectively accelerate the electron transfer rates, adjust the metal d-band center, optimize intermediates adsorption properties, and reduce the reaction energy barriers.

Heterogeneous strategy constructing a built-in electric field: CoP/FeP bifunctional electrode for overall water splitting

Development of non-noble bifunctional electrocatalysts for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) are of great significance under alkaline electrolytes for overall water splitting. In this work, CoP/FeP has been designed and constructed in situ on carbon fiber paper by using the bimetallic metal organic frameworks (MOFs) synthesis strategy. The heterogeneous CoP/FeP displays excellent catalytic activities in both HER and OER of the fully hydrolyzed semi-reaction. Remarkably, CoP/FeP is applied as the bifunctional electrode in anode and cathode to construct an overall water splitting apparatus, resulting in the low cell voltage and excellent stability. The exceptional electrocatalytic performance may be mainly attributed to the heterogeneous interface, which constructs a built-in electric field to provide electron to Co with electron-rich structure, resulting in the strong adsorption of H and weak adsorption of O2 on Co. This study provides an effective and controllable method for the design of self-supporting bimetal phosphide catalysts.

Self-supported Ru-Fe-Ox nanospheres as efficient electrocatalyst to boost overall water-splitting in acid and alkaline media

Developing electrocatalysts with high activity and durability for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in both acidic and alkaline electrolytes remains challenging. In this study, we synthesize a self-supported ruthenium-iron oxide on carbon cloth (Ru-Fe-Ox/CC) using solvothermal methods followed by air calcination. The morphology of the nanoparticle exposes numerous active sites vital for electrocatalysis. Additionally, the strong electronic interaction between Ru and Fe enhances electrocatalytic kinetics optimization. The porous structure of the carbon cloth matrix facilitates mass transport, improving electrolyte penetration and bubble release. Consequently, Ru-Fe-Ox/CC demonstrates excellent catalytic performance, achieving low overpotentials of 32 mV and 28 mV for HER and 216 mV and 228 mV for OER in acidic and alkaline electrolytes, respectively. Notably, only 1.48 V and 1.46 V are required to reach 10 mA cm−2 for efficient water-splitting in both mediums, exhibiting remarkable stability. This research offers insights into designing versatile, highly efficient catalysts suitable for varied pH conditions.

Experimental investigation on the electrodeposited nickel-based dichalcogenides for the efficient overall water splitting

Layered transition metal dichalcogenides are effective electrocatalysts for water splitting due to their unique properties such as high electrical conductivity, active site density, and catalytic properties. This study focused on the deposition of Ni-based dichalcogenides (NiX2, where X = S, Se, Te) onto a carbon cloth substrate using a simple one-step electrodeposition method at room temperature with different deposition times (10, 15, and 20 minutes). The optimized NiS2-15, NiSe2-15, and NiTe2-15 electrocatalysts showed excellent bifunctional electrocatalytic activity for both hydrogen evolution reaction and oxygen evolution reaction in alkaline media. The overpotential values for hydrogen evolution were ∼56 mV, ∼37 mV, and ∼75 mV for NiS2-15, NiSe2-15, and NiTe2-15, respectively, while the overpotential values for oxygen evolution were ∼220 mV, ∼170 mV, and ∼210 mV, respectively. The electrocatalysts maintained stability for 24 hours during the evolution reactions. The density functional theory calculations suggested that NiSe2 had a lower ΔGH* value due to its smaller bandgap and inherent metallic characteristics, which is consistent with the experimental results. These findings provide a new direction for designing NiX2 (X = S, Se, Te) nanosheets for electrocatalysis applications.

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 (0.05mmol, 0.1mmol, 0.2mmol, 0.3mmol) were doped and it was observed that the electrochemical results of the 0.2mmol Re doped Co3O4/ MWCNT (R0.2CO) was most efficient electrocatalyst which offers the OER overpotential of 298mV/dec to attain the 10mAcm−2 current density, lower Tafel slope (70mV/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.