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

A GaOOH/ZnBiNbO composite was constructed by loading dispersed GaOOH rods on the surface of ZnBiNbO 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/ZnBiNbO composite. The characterization results showed that ZnBiNbO was not destroyed by a high temperature and high pressure in the solvothermal process and that GaOOH was successfully dispersed on the surface of ZnBiNbO. Simultaneously, there was a red-shift of the absorbance edge for GaOOH/ZnBiNbO compared with those of pure ZnBiNbO and pure GaOOH. The band gaps of ZnBiNbO, GaOOH and GaOOH/ZnBiNbO were calculated to be 2.96 eV, 4.76 eV and 2.93 eV, respectively. The photocatalytic activity of GaOOH/ZnBiNbO was explored by degrading enrofloxacin under illumination. After ultraviolet light irradiation for 60 min, the removal rate of enrofloxacin with GaOOH/ZnBiNbO as a photocatalyst was 15.11% higher than that of pure ZnBiNbO 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 ·O > ·OH > h. The construction of the GaOOH/ZnBiNbO composite improved the performance of the single ZnBiNbO photocatalyst and single GaOOH photocatalyst, thereby increasing their practical application potential.