Enhancing the electrocatalytic performance of vanadium oxide by interface interaction with rGO and NiO nanostructures for electrochemical water oxidation

Abstract

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 V2O5 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 (η10 = 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 (Cdl = 43.18 mF cm−2), redox capability, and synergistic effects.