High-entropy heterostructure electrocatalyst with built-in electric field regulation for efficient oxygen evolution reaction

Abstract

Space-charge transfer is an effective strategy to enhance electrocatalytic activity by modulating the surface electron density of catalysts. Herein, a multichannel carbon nanofibers–supported FeCoNiCuMoSe high-entropy metal selenide heterojunction catalyst was designed to achieve an efficient electrocatalytic oxygen evolution reaction (OER). This catalyst uses the work function difference between NiSe₂ and (Co,Cu)Se₂ to induce a built-in electric field at the interface, which effectively promotes interfacial charge transfer and subsequently regulates the adsorption/desorption of oxygen-containing intermediates. Furthermore, constructing a high-entropy system and synergistic interactions between multiple elements accelerate the OER kinetics. In an alkaline electrolyte, the electrocatalyst exhibits excellent performance, requiring an overpotential of 187 mV to achieve a current density of 10 mA cm⁻² and maintaining excellent stability for at least 100 h without noticeable degradation. Herein, a novel perspective on the rational design of high-performance multiphasic electrocatalysts is presented, and robust technical support is provided for efficient and durable electrocatalytic OER.