Engineering adjacent Co₁–O_V sites for biomimetic oxygen activation via a tunable electron-relay mechanism toward wastewater purification

Efficient activation of molecular oxygen (O₂) into reactive oxygen species without external energy is vital for advanced oxidation processes (AOPs), which are, nevertheless, often limited by the sluggish electron transfer kinetics on heterogeneous catalysts. Inspired by natural enzyme behavior in the respiratory chain, herein we designed atomically neighboring Co single atom and oxygen vacancy (Co₁–O_V) dual sites on tungsten oxide, creating a biomimetic electron-relay pathway for O₂ activation under ambient conditions. In detail, Co₁–O_V electron delocalization strengthens the O₂ adsorption on O_V, by oxidizing the peroxymonosulfate (PMS) for the obtainment of a single electron on the Co₁ active site, reducing the energy barrier of O₂ activation, thereby producing singlet oxygen (¹O₂). Notably, via tuning the electronic state of Co₁, the PMS→Co₁–O_V→O₂ single electron-relay process can be quantitatively and regularly manipulated. These features enable the ¹O₂ generation rate up to at least threefold of traditional PMS-AOPs, and the pollutant degradation rates superior to previously reported PMS-AOPs heterogeneous catalytic systems. The catalyst is robust (>2000 min) and universality across practical applications. Our findings provide a new biomimetic strategy to realize ambient O₂ activation and advance the design of heterogeneous catalysts for next-generation sustainable catalytic technologies.