Electrocatalytic oxygen evolution by synergistically coupling layered double hydroxide Ni-based with MXene

Abstract Electrolysis presents a cost-effective and environmentally friendly approach for producing carbon-neutral hydrogen, addressing global environmental challenges. However, the slow kinetics of the oxygen evolution reaction (OER) pose a significant obstacle in many sustainable energy conversion processes. In this study, a novel two-dimensional (2D) Ti 3 C 2 T x MXene substrate was used to hybridize with Mo-doped NiCo phosphate nanostructures through a two-step hydrothermal process followed by phosphating calcination, resulting in a low-cost and efficient electrocatalyst. The porous, defect-rich Ti 3 C 2 T x flakes provide metal-like electrical conductivity and a large surface area, supporting the direct growth of active species and improving their catalytic performance for the OER. The synthesized Ni 1 Co 1 Mo 0·125 Px/MXene exhibited an overpotential of 314.6 mV at 10 mA cm −2 and a Tafel slope of 77 mV dec −1 , with an electrochemical double-layer capacitance (Cdl) of 7.1 μF cm −2 corresponding to a large electrochemically active surface area (ECSA). Electrochemical impedance spectroscopy (EIS) confirmed a low charge-transfer resistance, while chronoamperometry (CA) stability tests demonstrated robust long-term durability under continuous operation. This unique nanostructure enhances electrocatalytic activity due to the synergistic effects between the metal components, offering improved performance for the oxygen evolution reaction.