Bifunctional MnCo2Se4 nano-cubes directly grown on nickel foam for effective water oxidation

Abstract

Green and sustainable energy alternatives to replace fossil fuels are a topic of research in scientific community, thus yielding pursuit of advancing renewable energy systems with hydrogen emerging as a suitable and viable alternative. Efficient and non-precious metal catalysts are crucial for large-scale electrochemical water splitting yielding clean H₂. Here, a novel two-step hydrothermal synthesis approach to fabricate manganese–cobalt selenide nano-cubes grown directly on nickel foam (NF) (MnCo₂Se₄/NF) is adopted. Leveraging its hierarchically structured architecture, augmented active sites, and electrochemically active surface area, MnCo₂Se₄/NF material demonstrates exceptional electrocatalytic performance for both water oxidation and reduction. With an overpotential of 233 mV for oxygen evolution reaction (OER) and 187 mV for hydrogen evolution reaction at a current density of 10 mA/cm², MnCo₂Se₄/NF also exhibits a Tafel slope of 44 mV/dec for sluggish OER process. Notably, this nanocrystalline catalyst displays enhanced catalytic activity under alkaline conditions, accelerates water dissociation, and maintains good stability over 50 h. Outperforming state-of-the-art RuO₂, particularly in two-electrode assemblies with an overpotential of 218 mV at 10 mA/cm², this work offers a promising pathway for designing and manufacturing of innovative bifunctional electrocatalysts for efficient water splitting processes, thereby contributing to broader goal of sustainable energy production.