Construction of g-C3N4/BiOCl/CdS heterostructure photocatalyst for complete removal of oxytetracycline antibiotic in wastewater

Abstract

One of the vital topics in photocatalysis research is the development of novel photocatalytic nanomaterials for degradation of toxic pollutants in the natural water under visible light irradiation. Herein we report, for the first time, a facile hydrothermal synthesis of g-C3N4/BiOCl/CdS heterojunction for complete removal of oxytetracycline (OTC) antibiotic in wastewater. The suppression of electron-hole recombination rate was obtained after creation of the ternary heterostructure. Accordingly, the enhanced photoactivity was found in the prepared heterojunction photocatalyst as expected. Complete removal of OTC was obtained under natural sunlight irradiation. The removal of OTC follows the first-order reaction with the maximum rate constant of 0.023 min−1. The prepared photocatalyst still maintains its structural stability with high photocatalytic performance even after seven times of use. Photogenerated holes are the crucial species involved in the OTC removal while electrons and hydroxyl radicals play a subordinate role. Charge transfer at the interface of the ternary heterojunction is proposed to be the Z-scheme type. The present work shows a promising strategy to create a novel ternary heterojunction with an enhanced photoactivity for complete detoxification of harmful OTC antibiotic in the environment.