Defect-engineered Co3O4 with porous multishelled hollow architecture enables boosted advanced oxidation processes

Developing high-efficiency catalysts for advanced oxidation processes (AOPs) is significant for eliminating environmental pollutants. Herein we highlight rational architectural design coupled with defect engineering over catalyst promises advanced catalysis. Take widely-used Co3O4 as model material, we present defect-engineered Co3O4 with porous multishelled hollow architecture (MS-VO-Co3O4) for considerably boosted degradation of recalcitrant organics via peroxymonosulfate (PMS) activation. The special morphology regarding pore-abundant multi-shells with complex nanoconfined interior space contributes to active site exposure and mass diffusion. Significantly, theoretical calculations disclose that oxygen vacancies (VO) engineering can modulate surface electronic state, giving rise to strengthened binding energy and intensified electron transfer for PMS activation. Consequently, up to 46 times of catalytic enhancement can be achieved for MS-VO-Co3O4 relative to commercial Co3O4 towards 4-chlorophenol degradation (0.186 vs 0.004 min-1). This work would inspire more elegantly designed catalysts via architecture and defect engineering for various applications beyond AOPs.