Nearly 100% selective generation of singlet oxygen (¹O₂) via peroxymonosulfate activation over in-situ boron...

This study constructed a series of Co-B_x-O catalysts by introducing electron-deficient boron (B) atom to modulate the electronic structure of Co sites for peroxymonosulfate (PMS) activation, achieving nearly 100% selective generation of singlet oxygen (¹O₂). The introduction of the B element could make upward shift of the d-band center of the Co sites, and enhances the surface hydroxyl group density of the catalysts, improving the selective adsorption of the terminal oxygen of PMS. As a result, nearly 100% of ¹O₂ was formed with tiny content of other ROS such as sulfate radical (SO₄^·-), hydroxyl radical (OH). The steady-state concentration of ¹O₂ was experimentally confirmed to be linearly dependent on the B content. The induced ¹O₂ exhibited outstanding tetracycline (TC) degradation performance, with the optimal reaction rate constant as high as 0.446 min^-1. This work provides an efficient strategy for achieving ultrahigh selectivity in non-radical oxidation pathways for the advanced oxidation process.