Tetracycline Removal Under Solar Illumination Over Ag3VO4/mpg-C3N4 Heterojunction Photocatalysts

Ag 3 VO 4 /mpg-C 3 N 4 (mesoporous graphitic carbon nitride) heterojunction photocatalysts were prepared by anchoring tiny Ag 3 VO 4 particles on the nanosheet of mpg-C 3 N 4 . The prepared Ag 3 VO 4 /mpg-C 3 N 4 heterojunctions were used to remove tetracycline (TC), a kind of antibiotics widely released into the aquatic environment under solar irradiation. Compared with pure mpg-C 3 N 4 and Ag 3 VO 4 , Ag 3 VO 4 /mpg-C 3 N 4 displayed much higher photocatalytic activity (83.2% removal rate within 90 min under visible-light irradiation). Importantly, no apparent deactivation was observed for Ag 3 VO 4 /mpg-C 3 N 4 -40 after five cycles, inferring a good reusability. As confirmed by photocurrent measurement and photoluminescence spectra, the excellent photocatalytic property of Ag 3 VO 4 /mpg-C 3 N 4 was credit to the electron–hole separation enhancement at the formed heterojunction of two semiconductors. In addition, a possible mechanism and intermediate products for the Ag 3 VO 4 /mpg-C 3 N 4 photocatalysts toward the photodegradation of TC in aqueous solution under artificial sunlight radiation were proposed based on the scavengers trapping test, ESR spectra and a high-performance liquid chromatography (HPLC) coupled with mass spectrometer (MS) analysis. This investigation provides a low cost, green and easily practical approach to remove the antibiotics in the aquatic environment.