Dispersed GaOOH rods loaded on the surface of ZnBiNbO5 particles with enhanced photocatalytic activity toward enrofloxacin

Abstract

A GaOOH/ZnBiNbO₅ composite was constructed by loading dispersed GaOOH rods on the surface of ZnBiNbO₅ particles and characterizations, including SEM-EDS, XRD, FT-IR spectroscopy, XPS, and UV-Vis DRS, were performed to analyze the morphology, structure and optical properties of the GaOOH/ZnBiNbO₅ composite. The characterization results showed that ZnBiNbO₅ was not destroyed by a high temperature and high pressure in the solvothermal process and that GaOOH was successfully dispersed on the surface of ZnBiNbO₅. Simultaneously, there was a red-shift of the absorbance edge for GaOOH/ZnBiNbO₅ compared with those of pure ZnBiNbO₅ and pure GaOOH. The band gaps of ZnBiNbO₅, GaOOH and GaOOH/ZnBiNbO₅ were calculated to be 2.96 eV, 4.76 eV and 2.93 eV, respectively. The photocatalytic activity of GaOOH/ZnBiNbO₅ was explored by degrading enrofloxacin under illumination. After ultraviolet light irradiation for 60 min, the removal rate of enrofloxacin with GaOOH/ZnBiNbO₅ as a photocatalyst was 15.11% higher than that of pure ZnBiNbO₅ and was 29.29% higher than that of pure GaOOH. In addition, the contribution of the free radicals in the photocatalytic process was confirmed to be ·O₂⁻ > ·OH > h⁺. The construction of the GaOOH/ZnBiNbO₅ composite improved the performance of the single ZnBiNbO₅ photocatalyst and single GaOOH photocatalyst, thereby increasing their practical application potential.