Highly Efficient Photocatalytic Degradation of TC-HCl by Morphology Regulation of Ga₂O₃ Nanostructures

Tetracycline antibiotic contaminants have attracted more and more attention due to their high toxicity and the difficulty of their natural decomposition. Here, we have successfully regulated the morphologies of Ga₂O₃ photocatalysts (Ga₂O₃ QDs, Ga₂O₃ hollow spheres, and Ga₂O₃ micrometer rods) through a simple solvothermal and hydrothermal method and investigated their photocatalytic degradation of tetracycline hydrochloride (TC-HCl). It was found that Ga₂O₃ QDs showed the best photocatalytic performance due to their large specific surface area (61.1838 m² g^-1), wide bandgap (4.62 eV), etc. After the preparation conditions had been optimized, the Ga₂O₃ QDs synthesized at 240 °C and 10 h exhibited the best performance in degrading TC-HCl; after 500 W xenon lamp irradiation for 20 min, the degradation efficiency can reach 99% and the degradation rate reached 0.2988 min^-1. By trapping experiments, the main active substances in the degradation of TC-HCl by Ga₂O₃ were identified as a superoxide radical (^•O₂) and a hole (h⁺). This study provides a new idea of catalyst morphology regulation and a new method for efficient photocatalytic degradation of TC-HCl.