(2022) Journal of Environmental Chemical Engineering_Nitrogen-containing carbon hollow nanocube-confined cobalt nanoparticle as a magnetic and efficient catalyst for activating monopersulfate to degrade a UV filter in water

Tuan D.D., Kwon E., Phattarapattamawong S., Thanh B.X., Khiem T.C., Lisak G., Wang H., Lin K.-Y.A.

(Elsevier Ltd) Journal of Environmental Chemical Engineering ISSN: 22133437 Vol.10 Issue.2 Article No.106989 DOI: 10.1016/j.jece.2021.106989

While bis(4-hydroxyphenyl) ketone (BHK) represents one of the most typical UV filters, which, however, exhibits xenohormone toxicities, very few studies exist for investigating elimination of BHK from water. As sulfate radical-based oxidation processes are validated for degrading emerging contaminants, this current work attempts developing advantageous sulfate radical-based processes through activating monopersulfate (MPS) for eliminating BHK in water. Since cobalt (Co)-containing catalysts are effective catalysts for MPS activation, this study proposes to develop a Co NP-containing catalyst, in which Co NPs are confined in hollow N-containing carbon nanocube (HCoNC) derived from a cobaltic metal-organic framework (Co-MOF). The cubic Co-MOF would be firstly afforded through a surfactant-assisted method. The resultant cubic Co-MOF would be then modified with tannic acid (TAA) to etch its interior for affording the cubic Co-MOF with the hollow structure, which is subsequently converted into Co NP-containing hollow N- containing carbon nanocube (HCoNC) through carbonization. HCoNC can exhibit significantly superior catalytic activities than the non-hollow CoNC and Co₃O₄ nanoparticles for MPS activation to BHK degradation. The activation energy (Ea) for degrading BHK by MPS is 45.3 kJ/mol, which is much lower than reported values. HCoNC could be reusable over 5 consecutive BHK degradation cycles without decreasing catalytic activities. The MPS activation and plausible BHK degradation route by HCoNC+MPS is elucidated by experimental investigations as well as density functional theory (DFT) calculation to provide insightful mechanism of BHK degradation process. © 2022