Amorphous Titanium Dioxide-Based Heterojunction with Locally Enhanced Electron Transport Multipathways for High-Efficient Photodegradation of Tetracycline.

A novel amorphous titanium dioxide (AT)-based heterojunction, composed of AT, silver bromide, and silver nanoparticles (Ag NPs), was synthesized and designated as AgBr/Ag/AT-4%. The band structure and active species of AgBr/Ag/AT-4% composites were investigated, and the existence of multiple electron transport pathways in the composites was determined. The Channel I is an all-solid-state Z-scheme heterostructure formed between AT and AgBr by Ag acting as an electron transport bridge, and Channel II is excited by the localized surface plasmon resonance effect induced by the Ag NPs on the photocatalyst surface. The Channel III is an electronically bridged medium with Ti³⁺/Ti⁴⁺ redox coupling pairs and oxygen vacancy-mediated trap states constructed from defective structures. The activity of the sample was assessed by the photocatalytic degradation of tetracycline. It is hoped that this work will provide a new idea for the preparation of an amorphous titanium dioxide-based heterojunction with locally enhanced electron transport multiple pathways.