Facile fabrication of AgI/BiVO4 composites with enhanced visible photocatalytic degradation and antibacterial ability

Abstract Novel AgI/BiVO4 photocatalysts were successfully synthesized via a simple hydrothermal process for the first time. The synthesized AgI/BiVO4 composites were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Energy dispersive spectroscopy (EDS), High resolution transmission electron microscopy (HRTEM), Scanning electron microscope (SEM), photoluminescence (PL) spectra and UV diffuse reflectance spectroscopy (UV-DRS) techniques, respectively. The photocatalytic performances of the as-obtained samples were evaluated by photodegradation of rhodamine B (RhB) and killing of Pseudomonas aeruginosa (P. aeruginosa) under visible light irradiation. The 20% AgI/BiVO4 showed higher photodegradation and photocatalytic antibacterial activity than the pure AgI and BiVO4. 20% AgI/BiVO4 exhibits the best photocatalytic performance with almost all RhB decomposed within 150 min and the antibacterial rate could achieve over 99.99% after 30 min photocatalytic antibacterial reaction. The photocatalytic antibacterial mechanism of AgI/BiVO4 was investigated by radical trapping experiments. The results revealed that superoxide radical ( O2−) and holes (h+) were the dominant active species in the photocatalytic antibacterial process. Furthermore, the 20% AgI/BiVO4 still maintained a high activity after five cycle for killing of P. aeruginosa. The experimental results showed that the synthesized AgI/BiVO4 can be used in water treatment of degradating the organic pollutants and killing the water bacteria at the same time.