Electronic redistribution over the active sites of NiWO4-NiO induces collegial enhancement in hydrogen evolution reaction in alkaline medium

The activity-enhancement of a new-generation catalyst focuses on the collegial approach among specific solids which exploit the mutual coactions of these materials for HER applications. Strategic manipulation of these solid interfaces typically reveals unique electronic states different from their pure phases, thus, providing a potential passage to create catalysts with excellent activity and stability. Herein, the forma-tion of the NiWO4-NiO interface has been designed and synthesized via a three-step method. This strat-egy enhances the chance of the formation of abundant heterointerfaces due to the fine distribution of NiWO4 nanoparticles over Ni(OH)2 sheets. NiWO4-NiO has superior HER activity in an alkaline (1 M KOH) electrolyte with modest overpotentials of 68 mV at 10 mA cm-2 current density. The catalyst is highly stable in an alkaline medium and negligible change was observed in the current density even after100 h of continuous operation. This study explores a unique method for high-performance hydrogen gen-eration by constructing transition metal-oxides heterojunction. The XPS studies reveal an electronic redistribution driven by charge transfer through the NiWO4-NiO interface. The density functional theory (DFT) calculations show that the NiWO4-NiO exhibits a Pt-like activity with the hydrogen Gibbs free energy (DGH*) value of 0.06 eV compared to the Pt(DGH* =-0.02 eV).(c) 2023 Elsevier Inc. All rights reserved.

Automated summary

The activity-enhancement of a new-generation catalyst is achieved by the collegial approach among specific solids, which exploit the mutual coactions of these materials for HER applications. The formation of the NiWO4-NiO interface, designed and synthesized through a three-step method, leads to the formation of abundant heterointerfaces. This catalyst exhibits superior HER activity and stability in an alkaline electrolyte.