Ag bridged Z-scheme AgVO3/Bi4Ti3O12 heterojunction for enhanced antibiotic degradation

Abstract

Construction of heterojunction is an effective way to improve the photocatalytic activity of photocatalyst. In this work, a simple precipitation method was adopted to anchor rod-like AgVO3 on Bi4Ti3O12 nanosheets to form heterojunction. The results show that Ag can act as an electronic medium to construct Z-scheme heterojunctions, that more visible light can be absorbed and facilitates the separation of electron hole pairs compared with the pure Bi4Ti3O12. The AgVO3/Bi4Ti3O12 composites displayed superior photocatalytic photodegradation of tetracycline (TC) under visible irradiation (λ > 420 nm). 12%AgVO3/Bi4Ti3O12 (AgVO3 with the mass ratio of AgVO3/Bi4Ti3O12 = 12%) showed the highest photocatalytic degradation efficiency, 57% of TC was degraded within 60 min which was the 9.5 times and 2.5 times higher than pure AgVO3 and Bi4Ti3O12. The capture experiment results showed that ·O2− and h+ are the main active radicals in the process of TC degradation. The improved photocatalytic activity is attributed to the construction of Z-scheme heterojunction, which leads to expand the light absorption range and efficient separation of photogenerated carriers. In addition, the mechanism of the photocatalytic degradation of antibiotics was proposed.