Oxygen vacancy modulation of single atom cobalt-activated peroxymonosulfate for highly selective generation of singlet oxygen and effective degradation of organic pollutants in actual water bodies

Singlet oxygen ( 1 O 2 ) is an excellent reactive species with solid resistance to refractory pollutants, and it is critical to enhancing the generation of 1 O 2 in the persulfate system. In this work, we developed a vacancy-containing copper oxide supported Co single atom catalyst (Co SACs /CuO(O v )) containing abundant cobalt active sites for the activation of PMS to achieve efficient 1 O 2 selective generation, thereby exhibiting ultra-high ciprofloxacin removal efficiency. Density functional theory calculations revealed that Co SACs /CuO(O v ) adsorbed the single O atom from the SO 4 side chain of PMS, facilitating its oxidation into *OH and subsequent efficient production of 1 O 2 . The Co SACs /CuO(O v )/PMS system exhibited strong resistance to variations in pH and coexisting substances in water, and the toxicity of CIP was significantly reduced after treatment. Furthermore, when the Co SACs /CuO(O v ) catalyst was immobilized on the PTFE filter membrane, it maintained the CIP removal efficiency above 75 % for 20 h under low temperatures (0℃) and in various complex aqueous environments. This work provides new insights into the design of catalysts featuring single-atom active sites and high-efficiency 1 O 2 generation, which is essential for potential applications in water purification.