Synthesis and photocatalytic activity of CeO2-NbC-x catalysts for degrading oxytetracycline in aquaculture water bodies

The aquaculture water body is rich in antibiotics, which has caused great harm to the natural environment. It is urgent to adopt special means to degrade antibiotics from the source and reduce their impact on human production and life. In this study, the CeO₂@NbC (CeO₂-NbC-x (where x denotes the wt% of NbC)) catalyst was synthesized by the molten salt method, polyacrylamide gel method and heat treatment technology. Multiple characterization methods confirmed that there were no other impurities in the CeO₂-NbC-x catalyst, and a special contact was formed between the CeO₂ and NbC interfaces. The CeO₂-NbC-x catalyst exhibits high ultraviolet and visible light optical absorption coefficients. Using oxytetracycline hydrochloride as the target pollutant, the effects of catalyst concentration, pollutant concentration and pH value on the photocatalytic activity of the CeO₂-NbC-x catalyst were investigated. When the catalyst concentration, pollutant concentration and pH value were 2 g/L, 75 mg/L, and 5, respectively, the degradation percentage of CeO₂-NbC-x catalyst reached 99%. Based on capture experiments and band arrangement theory, a new photocatalytic mechanism of the CeO₂-NbC-x catalyst has been proposed. This research provides new ideas for the application of wide bandgap semiconductors couple semiconductors with metallic properties in the field of photocatalysis.