Photothermal-assisted photocatalytic degradation of tetracycline in simulated natural water by BiVO4/CuBi2O4 Z-scheme heterojunction: Mechanisms insight, degradation pathways and toxicity assessment

Abstract

The photothermal effect generated under illumination can increase the surface temperature of the catalyst, and enhance the migration rate of the photogenerated carrier and the activity of the catalytic reaction, which is an effective way to promote photocatalytic degradation of pollutants. In this study, a Z-scheme BiVO4/CuBi2O4 (BVO-CBO) heterojunction with 0D/1D structure was prepared by hydrothermal method. Compared with pure BVO and CBO, the temperature of the Z-scheme BVO-CBO heterojunction can reach 90.1°C after 180 S illumination, and the temperature of the BVO-CBO+TC solution system can rise to 39.5°C after 10 min, which has higher heating rate and photocatalytic performance than the monomer catalyst. The experimental results showed that the photogenerated electron transfer pathway combined with the photothermal effect effectively promoted the separation of photogenerated carriers and maintained a strong redox potential, so that the removal rate of tetracycline (TC) by BVO-CBO reached 85.0 % within 90 minutes, which was significantly higher than that of pure BVO (39 %) and CBO (33 %). In addition, the toxicity of intermediate products gradually decreased during TC degradation. In addition, the effects of reaction temperature, pH, concentration of TC, common aquatic substrates and simulated natural water on TC removal were also studied. The combination of its structural advantages, redox capabilities, and photothermal effect provided a promising approach to the treatment of antibiotic-contaminated water.