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

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 AgVO 3 on Bi 4 Ti 3 O 12 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 Bi 4 Ti 3 O 12 . The AgVO 3 /Bi 4 Ti 3 O 12 composites displayed superior photocatalytic photodegradation of tetracycline (TC) under visible irradiation (λ > 420 nm). 12%AgVO 3 /Bi 4 Ti 3 O 12 (AgVO 3 with the mass ratio of AgVO 3 /Bi 4 Ti 3 O 12 = 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 AgVO 3 and Bi 4 Ti 3 O 12 . The capture experiment results showed that ·O 2 − 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. • A novel Z-scheme heterojunction of AgVO 3 /Bi 4 Ti 3 O 12 was fabricated. • AgVO 3 /Bi 4 Ti 3 O 12 hybrid exhibits highly efficient activity for TC degradation. • The improved catalytic activity was ascribed to superior charge separation. • Step-scheme charge separation mechanism in AgVO 3 /Bi 4 Ti 3 O 12 was verified.