Visible-light-assisted activation of peroxymonosulfate (PMS) over CoOx @C/g-C3N4 composite for efficient organic pollutant degradation

As a promising advanced oxidation process , photo-assisted peroxymonosulfate (PMS) activation for wastewater treatment has attracted widespread attentions. However, rational design of synergetic and recyclable catalysts for PMS photo-activation remains a big challenge. In this study, a carbon layer-coated amorphous CoO x supported on graphitic carbon nitride (CoO x @C/g-C 3 N 4 ) composite was fabricated to drive visible-light-assisted activation of PMS for efficient organic pollutant degradation. Amorphous CoO x nanoparticles were in-situ grown on two-dimensional g-C 3 N 4 substrate, among which a carbon layer serves as a high-speed electron transmission channel, facilitating the separation of photogenerated electron-hole pairs and accelerating the Co 3+ /Co 2+ redox cycle. Simultaneously, the carbon layer provides a protective film to suppress Co leaching, thereby improving the catalytic activity and reusability. Owing to the unique heterostructure and synergetic effect, the optimized 6% CoO x @C/g-C 3 N 4 composite exhibits superior catalytic efficiency and excellent cycling stability towards the degradation of various organic pollutants, which displays nearly 100% elimination of tetracycline (TC) within 80 mins. The h + , SO 4 •- and •OH are determined as the main contributors in the visible light-assisted PMS activation system, and the possible catalytic mechanism is also proposed. This work demonstrates a feasible strategy for constructing synergetic and effective photo-activation PMS catalysts for water remediation.