Au nanoparticle sensitized blue TiO2 nanorod arrays for efficient Gatifloxacin photodegradation

Abstract

TiO₂ nanorod arrays have been widely used in photocatalytic processes, but their poor visible light absorption and rapid carrier recombination limit their application. Both introducing oxygen vacancies and using precious metals as surface plasmon resonance (SPR) stimulators are effective strategies to enhance their photocatalytic performance. Herein, Au nanoparticle sensitized blue TiO₂ nanorod arrays (Au/B-TiO₂) were successfully fabricated for efficient Gatifloxacin photodegradation. The degradation efficiency of Gatifloxacin was up to 95.0%. Moreover, the corresponding reaction rate constant (K_a) was up to 0.02007 min⁻¹. Additionally, it was suggested that Gatifloxacin could be subject to three different degradation pathways. The superior catalytic activity of Au/B-TiO₂ is a result of the combined effect of the two components. Firstly, TiO₂ nanorod arrays provide a larger surface area for Au deposition and act as efficient transfer channels. Secondly, the presence of oxygen vacancies in blue TiO₂ nanorod arrays enhances the catalytic activity. Thirdly, Au acts as a SPR activator, providing a large number of high-energy electrons in the photocatalysis process. Lastly, the improved light capture capabilities are essential for efficient removal of Gatifloxacin. This work provides a new approach for the construction of a high-performance heterojunction photocatalyst in advanced oxidation processes.