A Simple Model for the Oxygen Evolution Activities of Transition Metal Chalcogenides

High Resolution Image Download MS PowerPoint Slide Transition metal chalcogenides (TMCs) are among the most investigated precatalysts for alkaline oxygen evolution reaction (OER). However, the origins of their activity and the role of the nature of chalcogen atoms remain unclear. To address these questions, we developed analogous single-source precursors to synthesize structurally and morphologically alike CoS, CoSe, and CoTe phases, serving as ideal starting materials to isolate the chalcogens’ role for the OER. We uncover the importance of reliable active site quantification, intrinsic activity evaluation, and monitoring in situ structural changes during OER. In our electrochemical analyses, special emphasis is placed on accurate redox activity evaluation. Our results show that the in situ -formed layered oxyhydroxide phases have similar intrinsic activities. The nature of the chalcogen atom influences the number of active sites, leading to the geometric activity trend: CoSe > CoS > CoTe. These insights are crucial for the understanding and development of future electrocatalysts and application-oriented devices.