Highly Efficient Visible-Light-Driven Mn_0.2Cd_0.8S/g-C₃N₄ Heterojunction for the Photodegradation of Highly Toxic Tetracycline Antibiotics

Abstract

With the rapid advancement of modern science and technology, the damage of antibiotics to human health and ecosystem has aroused widespread concern. In this study, a Mn0.2Cd0.8S/g-C3N4 type II heterojunction was prepared. The effects of different loading ratios, catalyst dosage, and pH on the photocatalytic functions of the composites were investigated. When the additive dosage of 10% Mn0.2Cd0.8S/g-C3N4 was 1.20 g/L, and the pH of the tetracycline (TC) solution was 5, the photodegradation rate of TC (10 mg/L) was 98.4% under the irradiation of visible light for 120 min. After four cycles, the photodegradation rate of 10% Mn0.2Cd0.8S/g-C3N4 reached 96.8%, indicating good stability and recoverability. Furthermore, the study found that ·O2– was the dominant active species leading to the decolorization of TC in the process of photocatalysis. Based on its excellent photodegradation rate and great cycle utilization rate, the Mn0.2Cd0.8S/g-C3N4 composite provided a promising suggestion for photocatalytic degradation of antibiotics.