Visible Light Photocatalytic Inactivation of Resistant Bacteria Using BiVO4/g-C3N4

To study the inactivation effect of BiVO4/g-C3N4 (BiC) on pathogenic bacteria in aquaculture, BiVO4 and g-C3N4 nanosheet with different proportions were first used to composite by ultrasound to obtain materials with better catalytic effect. The germicidal efficacy was studied by two kinds of light sources, and the dynamics of its inactivation was studied. In order to observe the practical application effect, the inactivation stability of the recycled material was studied. The composition of BiC3:5 was observed by field emission scanning electron microscopy (SEM) and X-ray energy dispersive spectrum (EDS). In order to analyze the different bactericidal effects, the photoelectric properties of the bactericidal materials were studied by UV-Visible diffuse reflectance spectroscopy (DRS) and electrochemical methods. The inactivation mechanism of BiC3:5 photocatalytic free radicals was analyzed by quenching test. In the inactivation test, BiC3:5 showed a strong inactivation effect, and the material was stable. Through SEM and EDS analysis, g-C3N4 and BiVO4 formed an effective composite. The UV-visible test shows that BiC3:5 has a large wavelength absorption range and a relatively narrow band gap. The electrochemical test showed that the separation efficiency of electrons (e(-)) and holes (h(+)) in BiC3:5 was high. The analysis of free radical quenching showed that BiC3:5 produced e(-), h(+), and O-center dot(2)- during the inactivation of resistant Escherichia coli (E. coli), among which center dot O-center dot(2)- had a direct effect on the inactivation. This study provides an experimental basis for the inactivation of BiC in aquaculture.