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

Abstract

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 1O2, HO, SO4− and O2− 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 CN 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.