Design of copper oxide and oxygen codoped graphitic carbon nitride activator for efficient radical and nonradical activation of peroxymonosulfate

Rational regulation of stable graphitic carbon nitride (CN) for superior peroxymonosulfate (PMS) activation is important in the catalytic degradation of water contaminants. In this work, the copper oxide and oxygen co-doped graphitic carbon nitride (CuO/O-CN) was prepared via one-step synthesis and applied in activating PMS for oxytetracycline (OTC) degradation, displaying superior catalytic performance. Systematic characterization and theoretical calculations indicated that the synergistic effect between the oxygen site of CN and CuO can modulate the electronic structure of the whole composite further facilitating the formation of non-radical 1O2 and various reactive radicals. Results of the influencing factor experiments revealed that CuO/O-CN has a strong resistance to the environmental impact. The degradation efficiency of OTC in the real water environment even exceeded that in the deionized water. After four successive runs of the optimal catalyst, the OTC removal rate was still as high as 91.3%. This work developed a high-efficiency PMS activator to remove refractory pollutants via both radical pathway and non-radical pathway, which showed a promising potential in the treatment of wastewaters.