Efficient and Durable Sulfion Oxidation Coupled With Hydrogen Production via Cu@Cu ₂ S Heterostructured Nanowires

ABSTRACT Electrocatalytic sulfur oxidation‐assisted hydrogen evolution is a promising method that can efficiently degrade sulfur ions in recovered wastewater while cost‐effectively producing hydrogen. However, it still remains a great challenge to develop efficient and stable electrocatalysts with a well‐defined heterointerface and high sulfur tolerance. Herein, we present a facile and liquid‐phase approach to synthesis Cu@Cu ₂ S core‐shell heterostructure nanowires derived from copper nanowires at room temperature for robust sulfide oxidation reaction (SOR)‐assisted H ₂ generation. The Cu@Cu ₂ S core‐shell heterostructure nanowires exhibit superior SOR activity with an ultralow potential of 0.3 V (vs. reversible hydrogen electrode [RHE]) at a current density of 100 mA cm ⁻² . More importantly, the assembled hybrid system with Cu@Cu ₂ S displays remarkable durability over 216 h with negligible activity decay. Combined with the experimental characterizations and theoretical calculations, it was demonstrated that Cu@Cu ₂ S core‐shell heterostructure nanowires possessed reduced transition energy barriers in the rate‐determining *S ₃ to *S ₄ oxidation step and a higher integrated density of states, significantly optimizing adsorption/desorption energy of sulfur intermediates, thereby greatly boosting the catalytic activity and alleviating the sulfur poisoning. Our findings provide a new strategy to develop metal/sulfide core‐shell heterostructure electrocatalysts with substantially enhanced activity and stability.