N,S,O triply-doped carbon with nanotubes-interwoven nanosheets encapsulated Co nanoparticles for robust antibiotic destruction via activating peroxymonosulfate

The development of facile and effective approaches to regulate the stability and reusability of metallic Co catalytic materials towards peroxymonosulfate (PMS) activation for remediating antibiotic pollutants remains challenging. In this study, we develop a one-step pyrolysis strategy to fabricate three-dimensional porous architecture assembled with N,S,O-codoped carbon nanotube-interwoven hierarchically porous carbon nanosheets encapsulated Co nanoparticles (Co@NSOC), which serve as chainmail catalysts for stable and reusable degradation of tetracycline hydrochloride (TCH) through PMS activation. The optimal Co@NSOC-700-activated PMS system presents an excellent removal efficiency of 94.1 % for TCH within 10 min and a high cycling efficiency of 92.9 % after eight cycles. The encapsulated structure, abundant catalytic sites, superior hydrophilicity and strong magnetism contribute to the high performance. Further investigation demonstrates that both radical and nonradical pathways contribute to the TCH destruction, and 1O2 is verified as the dominant reactive substance. The possible degradation pathways and the toxicity of intermediates for TCH are evaluated. This work offers an innovative structure design and surface modulation strategy to fabricate robust catalysts towards environmental remediation.

Pt/CeO2 coated with polyoxometallate chainmail to regulate oxidation of chlorobenzene without hazardous by-products

Doping noble metal and acid functionalization were both valid approaches to facilitate oxidation of chlorobenzene on CeO₂-based catalysts, but their promotion effects were influenced by different orders of modification process. Because of strong interaction between metal and support and proper redox nature of CeO₂, Pt NPs were re-dispersed into single atoms on CeO₂ surface via "ex-solution". Companied with Pt loading, the enhancement of oxidizing ability led to generation of polychlorinated by-products. Herein, CeO₂-supported Pt was coated by HSiW chainmail to protect Pt from being exposed to Cl-contained atmosphere, and HSiW coating promoted activation of chlorobenzene. The as-prepared chainmail catalyst of HSiW/Pt/CeO₂ displayed a remarkable performance in catalyzing oxidation of chlorobenzene without any dichlorobenzene at realistic condition. By comparison, other catalysts with exposed Pt suffered from production of toxic by-products.