Ion-exchange synthesis Ag@Bi2WO6/FeWO4 nanosheet with white-LED-light-driven for efficient activation of peroxymonosulfate: Synthesis, characterization, and mechanism

Abstract

Purification of antibiotics through white-LED photocatalytic semiconductors is one of the most promising sustainable development strategies. Here, a novel Ag@Bi2WO6/FeWO4 (Ag@BWO/FWO) nanosheet with oxygen vacancies was constructed by Ion-Exchange method and photodeposition of Ag, and coupled with peroxymonosulfate (PMS) for the synergistic decontamination of tetracycline hydrochloride (TC) under white-LED-light. By combining theoretical with experimental analysis, “Tug-of-War” model was proposed to depict the transfer mode and process of carriers. The electrons at Fe2+ will migrate towards Ag and Bi by charge drift transfer, describing the competing effects of Ag and Bi on electrons at Fe2+ in a Tug-of-War model. Carriers were transferred to the catalyst surface and PMS during this process, weakening the recombination of internal electron-hole pair. Furthermore, mechanistic studies reveal that SO4-, O2-, 1O2 were the primary and OH is secondary radicals for TC decontamination, and an outstanding rate of elimination was achieved. This work has successfully applied ternary catalysts for efficient PMS activation under irradiation of white-LED-light and accomplished satisfactory pollutant removal efficiency, which offers potential for the construction and use of multiple catalysts in an efficient abating environmental pollution.