Laser-constructed 3D self-supported CoCu metal-organic framework electrocatalysts for efficient oxygen evolution reaction

The excellent electrocatalytic activity of metal-organic frameworks (MOFs) has shown great potential in applications, but has also posed outstanding challenges due to their poor conductivity and electrochemical stability. Here, we report a novel and promising self-supported oxygen electrocatalyst featuring bimetallic MOF nanosheets loaded on femtosecond-laser-constructed CoCrFeNi high-entropy alloy substrate (CCM/FHEA). This integrated design leverages synergistic advantages—including expansive specific surface area, rapid electrolyte exchange, and strong electronic interaction—to achieve exceptional oxygen evolution reaction (OER) activity and stability, with a small overpotentials of 231 mV to reach the current density of 10 mA·cm⁻² and a Tafel slope of 53.3 mV·dec⁻¹. Furthermore, this electrocatalytic system recorded excellent reaction stability over 300 h with a constant current density of 150 mA·cm⁻² at the potential of 1.56 V vs. RHE. Finite-element simulations demonstrate the intensified potential gradients and electric field intensity on the CCM/FHEA electrode surface, while density-functional theory calculations uncover the regulated electronic structure and reduced reaction energy barrier in post-formed CoCu-based oxyhydroxide analogue during OER. This work provides a feasible strategy for the rational design and construction of MOFs-based hierarchical self-supported electrocatalysts for efficient energy conversion technologies.