Synergetic FeMoSe@NiCo-LDH hybrid heterostructures as a stable and effective bifunctional catalyst for sustained overall water splitting and seawater splitting

Abstract

Designing cost-effective and highly active and stable earth-abundant-based bifunctional electrocatalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is significant, yet challenging task. In this work, we employed synergetic design of FeMoSe@NiCo-LDH heterostructures electrocatalyst to effectively enhance OER and HER performance in the alkaline media by addressing the lethargic kinetics. Combining FeMoSe and NiCo-LDH components as hybrid heterostructure promotes synergistic effects inherently, and influences adsorption free energy and charge transfer, and improves overall reaction kinetics and durability. The FeMoSe@NiCo-LDH hybrid heterostructure catalyst demonstrates low overpotential of 240 mVRHE for OER and 170 mVRHE for HER to drive 10 mA cm−2 in high-pH media. Upon integration into two electrode electrolysers, the synergetic FeMoSe@NiCo-LDH electrocatalyst delivers a stable cell voltage is 1.71 V (overall seawater splitting) and 1.65 V (overall water splitting), stability at 10 mA cm−2, demonstrating its spectacular bifunctional activity, commendable for the sustainable hydrogen generation. The FeMoSe@NiCo-LDH catalyst exemplifies an economically viable and environmentally sustainable approach for hydrogen generation on larger scale.