Theoretical design rules for the reconstruction of transition metal sulfides during oxygen evolution reactions

Abstract

During the oxygen evolution reaction (OER), reconstruction of transition metal sulfides (TMSs) is inevitable. However, the lack of a clear theoretical understanding of this process has impeded the development of effective reconstruction regulation strategies. In this study, we first explored the reconstruction mechanism of CoS₂ during OER from the perspective of electronic structure and identified two possible pathways: the OH-assisted mechanism and the O-assisted mechanism. Further verification showed that these mechanisms are universally applicable to other TMSs (e.g., FeS₂). Based on the reconstruction mechanism, we investigated the basic reasons for the influence of various regulation strategies, such as vacancy modification and facet engineering, on the reconstruction ability. This verified that the method of analyzing the change in the reconstruction ability of catalysts based on the reconstruction mechanism has a high degree of applicability. Importantly, we proposed a core regulation strategy: the coordination symmetry regulation strategy. Specifically, by breaking the symmetry of the surface coordination environment of TMSs (such as introducing heteroatom doping or strain), the reconstruction process will be facilitated. Our findings provide a comprehensive mechanistic explanation for the reconstruction of TMS catalysts and offer a new idea for the rational design of OER catalysts with controllable reconstruction capacity.