Peroxymonosulfate-based photocatalytic oxidation of tetracycline by Fe2(MoO4)3/Cd0.5Ni0.5S heterostructure; DFT simulation

Abstract

The current research is meant to develop novel semiconductor photocatalysts, for the decomposition of tetracycline (TC) as a model organic contaminant in the aquatic environment. The fabrication of Fe2(MoO4)3/Cd0.5Ni0.5S (FMO/CNS) composite has proven to be an effective method for improving the sustainability and photocatalytic activity of Cd0.5Ni0.5S (CNS). Under visible light irradiation, FMO/CNS nanocomposite demonstrated significant PMS activation which led to 1.36 and 1.81 times TC removal efficiency as compared to immaculate Fe2(MoO4)3(FMO) and CNS. FMO/CNS composite potentially promotes the segregation of electron-hole pairs (e−-h+) and exemplifies amazing photocatalytic performance for TC degradation. Its significant photocatalytic activity is due to its unique structure, which includes tiny pores on the surface that confine the PMS molecule to the interface. The FMO/CNS composite has significantly greater piezocatalytic activity than pure FMO and CNS, demonstrating the synergistic effect of FMO and CNS. In the degradation of TC, holes and key reactive radicals (•O2−/•OH/SO4−•) played a major role. Computational studies (DFT) estimates, including the determination of intermediates, confirmed that the hydroxyl addition and C–N cleavage pathways were responsible for TC degradation. As a result, this work delivers a new approach to developing novel photocatalysts with high photocatalytic activity for the abatement of organic contaminants in water.