Anchoring RuSe₂ on CoSe₂ nanoarrays as a hybrid catalyst for efficient and robust oxygen evolution reaction

Interface engineering is an effective strategy to regulate the oxygen adsorption strength and accelerate the kinetics of oxygen evolution reaction (OER) catalyst by using the synergistic effect and electronic coupling between different metals. However, the design and demonstration of efficient and strongly coupled interfaces remains a bottleneck in the progress of efficient and durable OER catalysts. Herein, we designedly anchored RuSe₂ nanoparticles to CoSe₂ nanosheet arrays support on nickel foam (NF) to fabricate a RuSe₂-CoSe₂ nanosheet arrays with robust structure and strong electron coupling. Co-MOF was used as a template to conduce Ru ion exchange and then the precursor was selenized at low temperature to obtain RuSe₂ modified CoSe₂ nanosheet arrays. Thanks to the strong electron coupling between Ru with Co and the unique nanoarray structure, RuSe₂-CoSe₂ exhibits excellent OER performance with ultra-low overpotential of 200 mV at current density of 10 mA cm^-2, and the performance did not degrade significantly during 100 h of continuous operation. Furthermore, the assembledRuSe₂-CoSe₂ (+)//Pt/C (-) can reach 50 mA cm^-2 in a two-electrode system with a low battery voltage of 1.61 V, which is superior to the commercial RuO₂ (+)//Pt/C (-) (1.79 V) electrode. This work provides an effective avenue for the design of highly active and durable electrocatalysts.