Fabrication of novel BiPO4/Ag3PO4@rGO hybrid composite for effective detoxification of tetracycline.

A practical photocatalytic method using efficient and nontoxic is crucial for wastewater treatment technology. The present study deals with the preparation of BiPO/AgPO@rGO heterojunction through hydrothermal process and utilized it for efficient degradation and detoxification of Tetracycline (TCL) antibiotic. The prepared composite was characterized by X-ray diffraction, UV-vis DRS spectroscopy, Scanning electron microscope (SEM), Transmission electron microscope (TEM) and XPS (X-ray photoelectron spectroscopy). From our study, it was evident that the addition of AgPO extensively improved the photocatalytic efficiency of BiPO with a degradation of the rate of 94.6% (k = 0.01783 min) towards TCL under visible light within 90 min irradiation. The heterojunction energy-band theory has been adopted to understand the mechanism of degradation. The improved efficiency was ascribed to the excellent charge transfer between the interface of p-n heterojunction and the improvement in the absorption of light. Furthermore, LC/ESI-MS/MS (liquid chromatography-electrospray ionization tandem mass spectrometry) carried out TCL degradation product identification to propose the degradation pathway. The biotoxicity assessment studies revealed that effective detoxification was observed during degradation. Thus, this work extends new methods for developing new BiPO-based heterojunction composites to meet the requirements for remediation of a contaminated aqueous environment.