Novel Cerium (IV) Oxide -Ti3C2- titanium dioxide heterostructure photocatalyst for pharmaceutical pollutants removal: Photocatalyst characterization, process optimization and transformation pathways

Abstract

Tetracycline (TC) is a widely applied antibiotic recognized for its potential negative consequences on human health and ecological balance. In this study, a novel photocatalyst, Cerium (IV) oxide -Ti3C2- titanium dioxide (CeMXT), was synthesized through sonochemical and impregnation techniques, subsequently subjected to comprehensive characterization employing diverse methods including XRD, SEM, TEM, HR-TEM, Raman, XPS, and BET. The optimization of TC degradation was pursued using the Response Surface Methodology (RSM), encompassing variables such as initial TC concentration, irradiation duration, photocatalyst dosage, and pH. The degradation efficacy was investigated through free radical trapping experiments, revealing the pivotal roles of OH and superoxide anion radicals. Remarkable degradation efficiency, reaching 94.70 %, was achieved under specific parameter conditions: 22.19 mg/L TC concentration, 104.13 min irradiation, 0.65 g/L photocatalyst dosage, and pH 4.72. This exceptional performance could be attributed to the elevated generation of oxidant species facilitated by the Z-scheme electron transfer heterojunction. Furthermore, LC-Mass analysis was employed to delineate the intermediates formed during TC photodegradation, culminating in proposing a conceivable degradation pathway. The impressive proficiency of the CeMXT photocatalyst underscores its potential application for effective large-scale treatment of persistent organic pollutants in wastewater treatment facilities. Additionally, comparative analysis with a recently developed photocatalyst highlights its promise as a viable alternative for the remediation of such contaminants in aquatic ecosystems.