Direct Z-Scheme Oxygen-vacancy-rich TiO2/Ta3N5 heterojunction for degradation of ciprofloxacin under visible light: Degradation pathways and mechanism insight

Abstract

An oxygen-vacancy-rich TiO2/Ta3N5 (Vo-TiO2/Ta3N5) composite material was constructed via a solvothermal method, and the photocatalytic degradation of ciprofloxacin (CIP) performance was investigated in-depth. The solvothermal synthesis method introduces oxygen vacancies in TiO2, and successfully combines Vo-TiO2 and Ta3N5 to form a Z-Scheme structure. As a narrow bandgap semiconductor, Ta3N5 increases the absorption of the catalyst in the visible light region. Oxygen vacancies form an intermediate energy level in TiO2, which promotes the separation of photogenerated electrons and holes. In addition, the Z-Scheme energy band structure formed by Vo-TiO2 and Ta3N5 enables more photogenerated carriers to participate in the photocatalytic reaction, so that the Vo-TiO2/Ta3N5 heterojunction structure has excellent photocatalytic degradation of ciprofloxacin (CIP) performance. Furthermore, Vo-TiO2/Ta3N5 also can degrade rhodamine B, Methylene Blue and kill Staphylococcus aureus. It demonstrates that the sample is a multifunctional catalyst. This research provides a basis for the development of new nanocomposite photocatalysts by combining defect engineering and heterostructure construction of two modified semiconductor methods.