A facile one-pot synthesis of Cu3(PO4)2/CuWO4 composite for efficient degradation of tetracycline in water: Unraveling the origin of synergistic interactions between the catalyst components

Abstract

This study presents a Cu3(PO4)2/CuWO4 composite catalyst (CuPW-1/1), synthesized using a facile coprecipitation method, as a promising catalyst for efficient degradation of tetracycline (TC) in water via H2O2- based advanced oxidation processes (AOPs). In a Fenton-like process, CuPW-1/1 was found to be 19 and 66 times more efficient in TC degradation than CuWO4 and Cu3(PO4)2, respectively. Moreover, the efficiency of the CuPW-1/1 composite in TC degradation can be further enhanced upon exposure of the reaction medium to ultraviolet (UV) light, achieving more than 90 % antibiotic removal in just 30 min of the reaction at very low catalyst loading and H2O2 dosage. The strongly enhanced activity of the composite catalyst in a Fenton-like process originated from the unique surface properties of this material which enabled a high dispersion of the main active component responsible for the activation of H2O2 (Cu3(PO4)2) and provided strong interface contact between copper(II) phosphate and copper(II) tungstate, promoting more efficient degradation of TC in a photocatalytic and photo-assisted Fenton-like processes due to the formation of type I heterojunction. The main oxidizing species responsible for the highly efficient degradation and mineralization of TC were hydroxyl radicals. Furthermore, it was established that the CuPW-1/1 composite can efficiently degrade TC in a complex water matrix and can be successfully reused several times without any significant decrease in its efficiency. The results of this study may have a significant impact on the development of new catalysts for H2O2-based AOPs addressed to water treatment under environmentally relevant conditions.