A heterostructured ternary transition metal oxide composite as an efficient electrocatalyst for the hydrogen evolution reaction

Abstract

A key method for hydrogen production is water electrolysis involving the oxygen and hydrogen evolution reactions. The efficiency of these processes is largely dependent on the use of effective electrode catalysts. Despite the high water-splitting catalytic activity of noble metals such as Pt, Ru, and Ir, their scarcity and costliness pose significant challenges. Although Fe and Fe-based compounds have recently been identified as promising alternative catalysts due to their abundance, affordability, and low toxicity, particularly under the alkaline conditions required for the hydrogen evolution reaction, both can be reduced to unstable forms during the reaction. To address this, the focus of the present study is on developing a ternary transition metal oxide electrocatalyst comprising Ni, Fe, and Co oxides. Thereby, we leveraged the synergistic interactions among them to provide a heterogeneous electrocatalyst for the hydrogen evolution reaction with a sufficiently low overpotential of 45 mV and suitably high Tafel kinetics of 44.99 mV dec−1 and long-term stability. The ternary transition metal oxide electrode showcased superior performance compared to one comprising binary transition metal oxides by achieving a lower overpotential and a better Tafel slope while maintaining catalytic stability even for 100 h at a current density of 1000 mA cm−2. This innovative approach offers a highly efficient alternative catalyst to Fe, which is known to have stability issues for hydrogen production, especially at high current density.