Facile synthesis of Ag@Ag2O–BiVO4 plasmonic p–n heterojunction photocatalyst for photodegradation of tetracycline

In this study, a plasmonic p–n heterojunction Ag@Ag2O–BiVO4 photocatalyst was successfully prepared by a simple chemical precipitation-reduction process. The obtained samples were tested by various measurements and the photocatalytic behavior in the decomposition of tetracycline (TC) under irradiation with visible light was studied. The photodegradation study exhibits that Ag@Ag2O–BiVO4 has the optimum activity and can efficiently degrade 83.52% of TC in 60 min by irradiation with visible light. Furthermore, the Ag@Ag2O–BiVO4 exhibited more pronounced visible light absorption and the best performances than the BiVO4 and Ag2O–BiVO4, which was mainly due to the LSPR of plasmonic Ag. The experimental radical trapping proved that the active species of the photocatalytic process act in the following order: ·O2− > h+ > ·OH. To find intermediates, the possible TC degradation pathways via HPLC–MS were also investigated. This research provides a successful method to develop a plasmonic photocatalyst with p–n heterojunction for wastewater treatment.