Electron‐Delocalized Cu ²⁺ Activates Spin Channels in Spinel Oxides to Selectively Produce ¹ O ₂ for Wastewater Treatment

Abstract

Abstract Blocked electron transfer in the catalyst during advanced oxidation processes causes sluggish singlet oxygen ( 1 O 2 ) generation efficiency and sacrifices catalyst stability. In this work, we propose an electron‐delocalization strategy that unlocks A Td 2+ ─O─B Oh 3+ electron‐transfer pathways within spinel oxide (Cu 0.8 Fe 2.2 O 4 ), inducing the intermolecular electron transfer of peroxymonosulfate (PMS) for selective 1 O 2 generation. In situ characterizations and theoretical calculations confirm that the electron‐delocalized Cu 2+ triggers a high spin‐state of O in Fe Td 2+ ─O─Fe Oh 3+ , thus creating a spin channel for the spontaneous intermolecular electron transfer of PMS from the Fe Oh 3+ adsorption site to the Fe Td 2+ adsorption site through Fe Td 2+ ─O─Fe Oh 3+ . This process allows for the simultaneous oxidation and reduction of PMS, thereby reducing the energy barriers for the formation of SO 4 •− and SO 5 •− radicals. Subsequently, the interfacial SO 4 •− rapidly oxidizes SO 5 •− into 1 O 2 , enhancing 1 O 2 generation efficiency without sacrificing catalyst stability. The selectivity of 1 O 2 in the Cu 0.8 Fe 2.2 O 4 /PMS system reaches 98.4%. Multiple pollutants are removed in the Cu 0.8 Fe 2.2 O 4 /PMS system without interference from coexisting substances. The scale‐up experiment realizes 100% contaminant removal during the continuous operation process (48 h). This work exhibits a novel strategy for selective 1 O 2 generation to achieve the goal of practical applications.