Interfacial and Vacancies Engineering of Copper Nickel Sulfide for Enhanced Oxygen Reduction and Alcohols Oxidation Activity

Rational design and construction of highly efficient nonprecious electrocatalysts for oxygen reduction and alcohols oxidation reactions (ORR, AOR) are extremely vital for the development of direct oxidation alkaline fuel cells, metal-air batteries, and water electrolysis system involving hydrogen and value-added organic products generation, but they remain a great challenge. Herein, a bifunctional electrocatalyst is prepared by anchoring CuS/NiS₂ nanoparticles with abundant heterointerfaces and sulfur vacancies on graphene (Cu₁Ni₂-S/G) for ORR and AOR. Benefiting from the synergistic effects between strong interfacial coupling and regulation of the sulfur vacancies, Cu₁Ni₂-S/G achieves dramatically enhanced ORR activity with long term stability. Meanwhile, when ethanol is utilized as an oxidant for AOR, an ultralow potential (1.37 V) at a current density of 10 mA cm⁻² is achieved, simultaneously delivering a high Faradaic efficiency of 96% for ethyl acetate production. Cu₁Ni₂-S/G also exhibits catalytic activity for other alcohols electrooxidation process, indicating its multifunctionality. This work not only highlights a viable strategy for tailoring catalytic activity through the synergetic combination of interfacial and vacancies engineering, but also opens up new avenues for the construction of a self-driven biomass electrocatalysis system for the generation of value-added organic products and hydrogen under ambient conditions.