The In-situ preparation of CoFe LDH/MOF electrocatalysts with 2D/2D structure and its enhanced electrocatalytic performance for OER

The preparation of non-precious metal catalysts employed in oxygen evolution reaction (OER) is of great important for hydrogen production via electrocatalytic water splitting. In this work, a 2D/2D CoFe LDH/MOF heterostructure was constructed on nickel foam (NF) by in-situ partial conversion of CoFe MOF to CoFe LDH, and evaluated as an effective OER catalyst. Owing to the unique 2D/2D heterostructure, substantial electrochemical active surface area (ECSA), superior electron conductivity, accelerated mass/charge transfer kinetics and synergistic effect between the two materials, LDH/MOF-6 h sample combining structural features of both MOF and LDH exhibited a lowest overpotential of 257 mV, a small Tafel slope of 50.71 mV·dec ‑1 at 20 mA cm -2 current density, along with a highest ECSA of 108 cm 2 (27,000 cm 2 g -1 ). Moreover, LDH/MOF-6 h sample demonstrated superior stability over 100 h of continuous reaction in alkaline electrolyte, which indicates that 2D/2D CoFe LDH/MOF heterostructure is a highly future-oriented material for OER applications.