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The crucial requirement for achieving the high-efficiency industrialization of electrochemical water splitting lies in the development of proficient electrocatalysts designed to moderate the energy barriers associated with both the hydrogen and the oxygen evolution reaction (HER and OER). Improving performance and efficiency is the main objective behind the search for new types of electrocatalysts for electrochemical water splitting. Existing electrocatalysts have limitations, such as high energy barriers and material stability issues, which hinder the overall effectiveness of water splitting. Therefore, the invention of new electrocatalysts with desired performance is desired to overcome these challenges. Herein, an interconnected vanadium oxide-reduced graphene oxide-nickel oxide (VrG/NiO) electrocatalyst is recognized for efficient OER performance. The flower-like spherical structure of V 2 O 5 adhered with NiO on the rGO surface and generated an effective interfacial interaction between the electrocatalyst materials. Among the different combinations, the desired ratio of VrG/NiO electrocatalyst exhibits a lower overpotential (η 10 = 155.4 mV) and Tafel slope (84.1 mV.dec−1) for OER in 1 M KOH. The VrG/NiO electrocatalyst showed stable performance after 5000 cyclic voltammetry cycles and chronopotentiometry (15 h) analyses. For overall water splitting, VrG/NiO attained a low cell voltage (1.73V@10mA cm−2). The efficient OER performance attained by the VrG/NiO electrocatalyst is due to its resourceful electrochemical active surface area (C dl = 43.18 mF cm−2), redox capability, and synergistic effects. [Display omitted] • A new combination of V 2 O 5 -rGO-NiO nanostructured electrocatalyst for water splitting. • Flower-like structure of V 2 O 5 on the rGO surface with NiO as an electrocatalyst. • Low overpotential (η 10 = 155.4 mV) and Tafel slope (84.1 mV.dec−1) for OER in 1 M KOH. • Stable OER performance after 5000 CV cycles and long-term chronopotentiometry (15h). • Higher ECSA and synergistic effect is key reason for efficient OER. [ABSTRACT FROM AUTHOR]

A key challenge in the development of sustainable water-splitting (WS) systems is the formulation of electrodes by efficient combinations of electrocatalyst and binder materials. Cellulose, a biopolymer, can be considered an excellent dispersing agent and binder that can replace high-cost synthetic polymers to construct low-cost electrodes. Herein, a novel electrocatalyst was fabricated by combining Fe2O3 and Ni on microcrystalline cellulose (MCC) without the use of any additional binder. Structural characterization techniques confirmed the formation of the Fe2O3–Ni nanocomposite. Microstructural studies confirmed the homogeneity of the ~50 nm-sized Fe2O3–Ni on MCC. The WS performance, which involves the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER), was evaluated using a 1 M KOH electrolyte solution. The Fe2O3–Ni nanocomposite on MCC displayed an efficient performance toward lowering the overpotential in both the HER (163 mV @ 10 mA cm−2) and OER (360 mV @ 10 mA cm−2). These results demonstrate that MCC facilitated the cohesive binding of electrocatalyst materials and attachment to the substrate surface. In the future, modified cellulose-based structures (such as functionalized gels and those dissolved in various media) can be used as efficient binder materials and alternative options for preparing electrodes for WS applications. [ABSTRACT FROM AUTHOR]