Highly Efficient Bi4Ti3O12/g-C3N4/BiOBr Dual Z-Scheme Heterojunction Photocatalysts with Enhanced Visible Light- Responsive Activity for the Degradation of Antibiotics

A novel Bi4Ti3O12/g-C3N4/BiOBr(BTO/CN/BOB) composite was synthesized by a solvothermal-mechanical mixed thermal method. The composition, structure, and micromorphology of the samples were analyzed. The BTO/CN/BOB composite photo-catalyst shows better photocatalytic performance for tetracycline hydrochloride (TC) degradation compared to Bi4Ti3O12 and binary composite photocatalysts. The highest degradation rate of TC can reach 89.84% using the BTO/CN/BOB photocatalyst under the optimal conditions, and BTO/CN/BOB still exhibits good photocatalytic properties after recycling. Moreover, it also shows good photo-degradation activity for different kinds of antibiotics, implying its wide application prospect. The photocatalytic performance and reuse stability of BTO/CN/BOB were significantly improved, which may be because of the enhanced spectral absorption range and efficient electron transfer capability by the synergistic effect and interaction among Bi4Ti3O12, BiOBr, and g-C3N4. Finally, the possible degradation pathway and electron transfer mechanism of the dual Z-scheme heterojunction are proposed.