Effect of pH on the microstructure of β-Ga2O3 and its enhanced photocatalytic activity for antibiotic degradation.

Semiconductor photocatalysis has become the focus of recent research on antibiotic treatment because it is a green and efficient technology. In this study, α-GaOOH with several novel microstructures has been synthesized at a low temperature and its subsequent thermal transformation. The influence of pH on the synthesis of α-GaOOH is studied, and the results indicate that pH played an important role in the microstructures of α-GaOOH and β-Ga2O3. All Ga2O3 samples possess macro-mesoporous network structures and exhibits a remarkable photocatalytic activity for antibiotic degradation. The photoelectron chemical tests show that the separation efficiency of photogenerated charge carriers of Ga2O3-7.0 is higher than that of other Ga2O3. The enhanced photocatalytic activity of Ga2O3-7.0 is mainly ascribed to its morphology and oxygen vacancy. The active species trapping and photoluminescence measurement experiments indicate that OH and O2- are the major active species contributing to the photocatalytic process. This study will bring about the potential application in treatment of the antibiotic pollutants.