Construction of Super-Small-Sized BiVO4@SiO2 Composites with High Photocatalytic Performance for Tetracycline Degradation

The ubiquitous presence of tetracycline in water sources due to its prevalent usage in antibiotics poses a potential risk to ecosystems and to human health. There is therefore a dire need for efficient methods of tetracycline removal. To this end, we constructed a series of super-small-sized BiVO4 composites with different loading amounts of 5 wt%, 10 wt%, 15 wt%, 20 wt%, and 25 wt% on SiO2 support by a hydrothermal–calcination method for efficient photocatalytic degradation of tetracycline. XRD and SEM results revealed that these composites all exhibited good crystallinity and well-dispersed morphologies. Particularly, the 20 wt% BiVO4@SiO2 of this series of composites showed superior photocatalytic performance, with 84.1% efficiency in tetracycline degradation, higher than any of its counterparts. This can be explained by its wide light-absorption range and high charge-separation efficiency, as confirmed by UV-Vis absorption spectra and quenched fluorescence spectra. This work offers a new method for the design and construction of tetracycline degradation photocatalysts.