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 was-tewater treatment has attracted widespread attentions. However, rational design of synergetic and re-cyclable catalysts for PMS photo-activation remains a big challenge. In this study, a carbon layer-coated amorphous CoOx supported on graphitic carbon nitride (CoOx @C/g-C3N4) composite was fabricated to drive visible-light-assisted activation of PMS for efficient organic pollutant degradation. Amorphous CoOx na-noparticles were in-situ grown on two-dimensional g-C3N4 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 Co3+/Co2+ 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% CoOx @C/g-C3N4 composite exhibits superior cat-alytic 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+, SO4 center dot-and center dot 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. (c) 2023 Elsevier B.V. All rights reserved.