Bimetallic metal-organic frameworks as versatile electrocatalysts for water splitting in neutral and alkaline environments

Metal-organic frameworks (MOFs) have gained attention as potential candidates for water-splitting catalysis due to their ability to offer appropriate surface-active sites that facilitate the reaction. Traditionally, precious metals served as electrocatalysts. This study presents a less explored method of preparing hexagonal Bimetallic MOFs (NiCo-MOF/NF) for HER (Hydrogen Evolution Reaction) and OER (Oxygen Evolution Reaction) using a simple and environmentally friendly one-step solvothermal approach. Due to its distinctive porous structure and nano-sized crystalline framework., along with its extensive electrochemical surface area, the advanced electrocatalyst (referred to as NiCo-MOF/NF) exhibited outstanding electrochemical performance characterized by an impressively low Overpotential (60 mV/150 mV at 10 mA cm⁻² for HER/OER) and a very high current density (460 mAcm⁻² / 471 mAcm⁻² for HER/OER) within a narrow potential range. The Tafel slope of the NiCo-MOF/NF electrocatalyst was measured at 28 mV dec⁻¹ for the HER and 45 mV dec⁻¹ for the OER, indicating rapid kinetics at the surface of the catalyst. Furthermore, it displayed excellent stability during a 100-hour stability test of chronopotentiometry. This study reports a stable bimetallic NiCo-MOF/NF electrocatalyst in alkaline and neutral media.