Synergistic MoO2@Co3O4 electrocatalysts: A cost-effective approach for efficient alkaline water splitting using electrochemical process

Abstract

Efficient overall water splitting in alkaline electrolytes remains a critical target for various energy-related applications, necessitating the development of materials having potential of catalyzing hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) simultaneously with high venture and efficiency. This study focuses on the synthesis of affordable non-noble metal-based electrocatalysts using simple and time-efficient methods. Specifically, it highlights the development of MoO₂, Co₃O₄, and MoO₂@Co₃O₄ composite catalysts fabricated via electrodeposition on stainless steel substrates. The synthesized composite materials demonstrated superior electrochemical performance, with the MoO₂@Co₃O₄ composite in a 1:2 M ratio exhibiting significantly enhanced catalytic activity and reduced overpotentials for overall water splitting. The catalyst shows OER and HER activity at 143 mV vs RHE and 177 mV vs RHE over-potentials, which is very low. Also, the catalyst exhibited excellent durability, maintaining stability for up to 23 h in alkaline electrolyte conditions. The synergistic interaction between molybdenum and cobalt oxides was found to facilitate both HER and OER, leading to improved catalytic efficiency at low overpotentials. This approach provides a promising pathway for the integration of robust, cost-effective electrocatalysts, critical for advancing sustainable energy technologies.