MXene Supported Cobalt Layered Double Hydroxide Nanocrystals: Facile Synthesis Route for a Synergistic Oxygen Evolution Reaction Electrocatalyst

Abstract

The development of reliable electrolyzers is closely related to the development of a cost-effective highly active and stable electrocatalysts for the oxygen evolution reaction (OER). Herein, a simple method is used to synthesize a non-noble metal-based electrocatalyst for OER by synergistically coupling a catalytically active cobalt layered double hydroxide (Co-LDH) with a highly electrically conducting 2D transition metal carbide, Ti₃C₂T_x MXene. The synergy between these two bidimensional materials (Co-LDH and Ti₃C₂T_x), evidenced by coupling electron energy loss spectroscopy and density functional theory simulations, results in superior electrocatalytic properties and makes possible having an excellent and stable oxygen evolution electrocatalyst. Moreover, the oxidative-sensitive MXene structure is preserved during the synthesis of the composite and the formation of a well recovering Co-LDH phase avoids the irreversible oxidation of MXene at high potential values, which may affect its conductivity. With an overpotential of ≈330 mV at a current density of 10 mA cm⁻² the catalyst exhibits a higher catalytic activity toward OER than commercial IrO₂ catalysts.