Uncovering the pathway of peroxymonosulfate activation over Co0.5Zn0.5O nanosheets for singlet oxygen generation: Performance and membrane application

Singlet oxygen (1O2) exhibits excellent activity for degradation of refractory pollutants and strong resistance in a wide pH range and harsh environment. The efficient generation of reactive oxygen species is vital for the treatment of wastewater in peroxymonosulfate (PMS) system, but how to boost the selectivity of 1O2 still remains a great challenge. Herein, we developed an ultrahigh efficiency of solid solution Co0.5Zn0.5O (CZO) nanosheets exposed abundant cobalt active sites for PMS activation. The dual Co-Zn sites residing at the CZO surface selectively adsorbed specific O sites of PMS, therefore promoting the generation of 1O2 with 100% selectivity. The CZO/PMS system showed great adaptability to inorganic ions and pH value with the exclusive 1O2 species, and the toxicity of antibiotic contaminants was markedly declined after treatment. The CZO nanosheets were attached to fibrous membrane to apply in continuous degradation of organic pollutants with high removal efficiency (95%) over 10 h. This study provides new insights into the development of highly selective catalysts to 1O2 generation and highlights their potential applications in water purification.