Interfacial Engineering of Hierarchical Iron Oxysulfide Integrated MoS2 Heterostructures for Enhanced Oxygen Evolution Electrocatalysis

Abstract

Interfacial engineering plays a key role in enhancing the performance of electrocatalysts for the oxygen evolution reaction (OER). In this study, we report the development of a hierarchical heterostructure composed of iron oxysulfides integrated with MoS₂ on nickel foam (Fe-SO@MoS₂/NF) to serve as an advanced OER electrocatalyst. The vertically aligned morphology by growing layered MoS₂ on iron oxysulfides can facilitate efficient mass transport, accelerate reaction kinetic and improve ion diffusion at the catalyst-electrolyte interface. Surface modification at the interface is favorable to improving the conductivity and boosting the catalytic activity. Electrochemical measurements reveal that the optimized heterostructure demonstrates superior OER performance, with a low overpotential of 253 mV at 10 mA cm⁻² and Tafel slope of 62.1 mV dec⁻¹. The enhanced catalytic activity can be attributed to the well-engineered interface between iron oxysulfides and MoS₂, which promotes rapid electron transfer and stabilizes the catalyst under operational conditions. Furthermore, the long term stability of the catalyst under alkaline conditions highlights its potential for industrial water-splitting applications. This work gives a comprehensive understanding of the role of interfacial engineering in hierarchical heterostructures and opens new avenues for designing efficient transition metal oxysulfides-based OER electrocatalysts.