Effective degradation of aqueous bisphenol-A using novel Ag2C2O4/Ag@GNS photocatalyst under visible light

Photocatalytic oxidation of toxic pollutants is a proficient technique to solve the problems associated with the treatment of bisphenol-A which is classified as 1B reprotoxic substance. In this paper, Ag2C2O4/Ag@GNS nanocomposite whereas Ag and graphene nanosheets (GNS) used as the charge carriers, which is combined through peroxymonosulfate (PMS) for the removal of bisphenol-A (BiP-A) for the first time. The XRD, UV-DRS, SEM, and TEM studies were performed to confirm the phase structure and the purity. Ag2C2O4/Ag@GNS nanocomposite exhibited superior photocatalytic performance and removal rate when compared with pure Ag2C2O4 and pure GNS. In Ag2C2O4/Ag@GNS photocatalyst, the deposited Ag on the surface of Ag2C2O4 rods effectively formed a metal and semiconductor heterostructure, thus photogenerated charge carriers were separated easily by the surface plasmon resonance effect (SPR) effect of noble Ag. Hence charge carriers lifetime has been extended to a great extent for the better photocatalytic performance. The experimental results confirmed that the O-2-, OH, SO4- radicals were played major role in the photolysis process. Furthermore, the effect of the photocatalyst & PMS concentration, pH and co-existing ions towards the BiP-A degradation were studied in detail. According to the mass spectroscopy studies BiP-A pollutant was effectively deteriorated into smaller molecules and CO2, H2O. Furthermore, we have proposed the possible degradation pathway and photocatalytic mechanism for better understanding. (c) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

In this study, Ag2C2O4/Ag@GNS nanocomposite combined with peroxymonosulfate (PMS) was used for the first time to remove bisphenol-A (BiP-A). The nanocomposite exhibited superior photocatalytic performance compared to pure Ag2C2O4 and pure GNS. The experimental results revealed the significant role of O-2-, OH, and SO4- radicals in the photolysis process. The study also investigated the influence of photocatalyst and PMS concentration, pH, and co-existing ions on the BiP-A degradation, and proposed a possible degradation pathway and photocatalytic mechanism.