Cation defect engineering in LaCoO3 perovskite as the “Two birds one stone” strategy to enhanced Fenton-like reaction: Regulating Co spin state and optimizing electron transfer ability

•Cation defect engineering achieved “Two birds one stone” in Fenton-like reaction.•VLa could regulate the spin states of Co3+ to trigger PMS* generation.•The enhancement of Co 3d − O 2p covalency caused by VLa could boost ROS generation.•The LCO-3/PMS system followed nonradical-dominated and radical-assisted mechanism.•The LCO-3/PMS system could effectively and stably remove micropollutants.