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.

Automated summary

In this study, a bifunctional electrocatalyst with abundant heterointerfaces and sulfur vacancies on graphene (Cu1Ni2-S/G) was prepared for oxygen reduction and alcohols oxidation reactions (ORR, AOR). The Cu1Ni2-S/G catalyst showed significantly enhanced ORR activity with long term stability and achieved a high Faradaic efficiency for ethyl acetate production during AOR. The study highlights the synergistic effects of interfacial coupling and vacancies engineering in tailoring catalytic activity and opens up new avenues for self-driven biomass electrocatalysis systems.