Photocatalytic Degradation of Tetracycline Hydrochloride by Zinc oxide/Polypyrrole/Carbon nanotubes

Abstract

AbstractIn this study, the intermediates of the photocatalytic degradation of tetracycline hydrochloride (TC‐HCl) were analyzed by high performance liquid chromatography‐mass spectrometry. The doping of polypyrrole (PPy) and carbon nanotubes (CNTs) increased the reaction rate of TC‐HCl degradation by ZnO. The prepared ZnO has a large specific surface area, which can improve the adsorption performance. The introduction of PPy and CNTs can promote electron transfer and reduce the recombination of photogenerated electron hole pairs in the composite material ZnO/PPy/CNTs(ZPC), and the photocatalytic performance of the composite sample is improved. In addition, the new visible light catalyst has strong degradation effect on TC‐HCl. Using tetracycline hydrochloride as a pollutant, the photocatalytic degradation performance of each sample was analyzed. After 240 min of photoreaction, the Degradation rate of TC‐HCl (DTC‐HCl) by ZnO was 24.1 %, while that by ZPC was 91.5 %. Meanwhile, the intermediates of photocatalytic degradation of TC‐HCl were analyzed by high performance liquid chromatography‐mass spectrometry. The peak intensity of TC‐HCl from adsorption equilibrium to the end of the photocatalytic reaction occurred at a retention time of about 10.05 min and decreased with the increase of the reaction time. This indicates that TC‐HCl is broken down into small molecules during the reaction. Through the analysis of intermediates and active species, the degradation pathway of tetracycline hydrochloride was deduced.