Engineering a Core–Shell Heterostructure via Oxygen–Sulfur Distribution for Electrocatalytic Oxygen Evolution

Commercial applications of electrochemical energy conversion and storage devices are particularly important for carbon neutrality. However, addressing the bottleneck of high overpotential and sluggish kinetics of the oxygen evolution reaction (OER) is still challenging. Herein, we present a surface modification strategy to facilitate oxygen-based intermediate adsorption/desorption dynamics via constructing a core–shell Mo–Co3O4/CoS2 heterostructure with controlled sulfurization thickness. Multiple characterization investigations demonstrate that the synchronous introduction of Mo and O–S interfaces optimizes the interfacial electronic coupling interaction. Additionally, more Co3+ active sites and oxygen vacancies are generated from this regulated heterostructure, which in turn synergistically enhance the charge kinetics and lower the electrocatalytic energy barrier. Remarkably, Mo–Co3O4/CoS2 manifests an outstanding OER performance with only a 260 mV overpotential and boosted corrosion resistance. This study showcases an innovative and effective strategy to precisely modulate O–S heterostructure catalysts for electrochemical energy-related applications.