Facilitating peroxymonosulfate activation for effective antibiotics degradation from drinking water by photoelectrocatalytic system using MoS2 embedded carbon substrate

• DOI: 10.1016/j.cej.2022.139591
• Publication Date: 2022-10-06T17:18:07Z
• Authors: Zexiao Zheng; Zuyao Zhang; Ka Chun James Wong; Cheuk Wai Lung; Musharib Khan; Juhua He; Ashutosh Kumar; Irene M.C. Lo
• Keywords: Molybdenum disulfide; Antibiotics; 02 engineering and technology; 0210 nano-technology; Peroxymonosulfate; Drinking water treatment

The inefficiency of conventional water treatment technologies for the treatment of antibiotics has become a global concern. Herein, a promising photoelectrocatalytic (PEC) system enhanced by PMS was developed to treat antibiotics in drinking water in which a modified molybdenum disulfide embedded carbon cloth photoanode (namely 1T/2H-MoS2@C/CC, 1T and 2H for hexagonal and trigonal structures) served as a photoanode. The 1T/2H-MoS2@C/CC photoanode exhibited enhanced PEC performance due to the construction of the 1T rich structure. Under the synergetic effect of PEC and PMS, 2 ppm norfloxacin was completely removed in 30 min by the 1T/2H-MoS2@C/CC photoanode at a 1.5 V applied potential with 40 ppm PMS addition. Mechanistic investigations demonstrated that O-1(2), HO center dot, SO4 center dot- and O-2(center dot-) contributed to norfloxacin degradation, and the PMS activation pathways for the generation of these reactive species were also revealed. The intermediates of NOR degradation by the PEC/PMS system were analyzed, suggesting that the C-N bond, piperazine ring, and fluoride group on NOR molecular framework were attacked. The resistance of the PEC/PMS system to different water matrices and good reusability (87.6% at the fifth cycle) and stability (0.05 mg/L Mo4+ leaching) of the 1T/2H-MoS2@C/CC photoanode ensured the excellent practical potential of the developed PEC/PMS system. Overall, the PEC/PMS system with 1T/2H-MoS2@C/CC as the photoanode is proven to be feasible for practical antibiotics removal from drinking water.