Modulation of Mo–Fe–C Sites Over Mesoscale Diffusion‐Enhanced Hollow Sub‐Micro Reactors Toward Boosted Electrochemical Water Oxidation

Abstract Simultaneously engineering the mesoscale mass transfer and surface reactions on the electrode can promote the kinetics of oxygen evolution reaction (OER). Herein, it is reported that the simultaneous modulation of the mesoscale diffusion and Mo–Fe–C sites formation over monodispersed hollow Fe@MoS 2 –C sub‐micro reactors for boosted OER performance. According to finite element simulation and analysis, the hollow nanostructured MoS 2 –C host possesses better mesoscale diffusion properties than its solid and yolk–shell counterparts. Notably, the sulfur vacancies and intercalated carbon in the sub‐micro reactor offer a unique microenvironment for Fe anchoring on Mo–Fe–C sites. The stability and activity of the sites are revealed by theoretical calculations. The resultant Fe@MoS 2 ‐C presents an OER overpotential of 194 mV, which is much better than those of the Fe‐based single‐atom catalysts reported in the data. This monodispersed sub‐micro reactor involves the modulation of mesoscale diffusion and single‐atom sites, and it may have broad prospects for complex electrocatalytic reactions.