Boosting photocatalytic degradation of levofloxacin over plasmonic TiO2-x/TiN heterostructure

Semiconductor photocatalysis holds great promise as a method for addressing the issue of antibiotic pollution in water. However, the wide band gap and low carrier separation rate present significant challenges that restrict the water purification efficiency of photocatalytic materials. In this study, a novel TiO2-x/TiN@C heterojunction was prepared through a typical hydrothermal synthesis and carbon thermal reduction approach, which was utilized for the photocatalytic degradation of levofloxacin (LEV) antibiotics. TiO2-x contains various titanium oxides, including TiO2, Ti2O3, and Ti3O5, and possesses a narrow band gap, enabling efficient absorption of visible light. The visible light absorption ability is further enhanced when it forms a heterojunction with plasmonic titanium nitride, which exhibits good carrier separation ability. The results demonstrated that the degradation efficiency of TiO2-x/TiN@C for levofloxacin under visible light irradiation was significantly superior to that of TiO2-x@C and TiN without a heterostructure. Characterization tests and mechanistic analysis have revealed that the coupling of the heterostructure with localized surface plasmon resonance (LSPR) enhances photocatalytic activity. Additionally, the combination of photocatalysis with advanced oxidation methods has exhibited excellent catalytic degradation performance. This research provides novel insights into fabricating efficient LSPR-enhanced photocatalytic systems and a comprehensive understanding of the degradation pathways for LEV.