Highly efficient ternary NiO/MoS2/BiVO4 heterostructure for electrocatalytic HER/OER applications

Abstract

The field of ternary-based electrocatalyst design and fabrication has attracted considerable attention due to the unique physio-chemical and heterostructural properties exhibited by electrode materials in the realm of fuel generation. In this study, we present a straightforward method for efficiently constructing an electrocatalyst capable of facilitating the electrocatalytic splitting of H2O. Our approach involves the assembly of NiO nanoparticles onto MoS2 and BiVO4 using ultrasonication. Spectroscopic analysis reveals the presence of moderated electronic configurations resulting from a robust chemical interaction within the nanostructure. This interaction induces a charge shift from Ni2+ to Mo6+/Mo4+ across the interfacial Mo–S–Ni bond, leading to an increase in active sites and facilitating charge/mass transfers for the OER and HER within the nanostructures. Furthermore, the NiO/MoS2/BiVO4 nanostructure exhibits exceptional catalytic performance under alkaline conditions. It demonstrates a low overpotential of 300 mV for the OER and 95 mV at 10 mA cm−2 for the HER. Importantly, the nanostructured electrode maintains remarkable electrochemical stability for both HER and OER, as evidenced by minimal voltage fluctuations even after continuous operation for 24 h. This work highlights a simple yet significant strategy for optimizing electronic configurations using dual-functional transition metal-based electrocatalysts in the context of H2O splitting.