Oxygen Vacancy-Enhanced Ultrathin Bi2O3–Bi2WO6 Nanosheets’ Photocatalytic Performances under Visible Light Irradiation

The oxygen vacancy caused by ultrathin structures would be introduced into the semiconductor photocatalyst to boost its photocatalytic activity. Herein, ultrathin Bi2O3–Bi2WO6 nanosheet composites have been successfully synthesized via a facile hydrothermal method. Compared to pure Bi2WO6 nanosheets, the Bi2O3–Bi2WO6 nanosheet composites possess abundant oxygen vacancies, which was confirmed by the positron annihilation spectra. The ultrathin Bi2O3–Bi2WO6 nanosheet composites exhibited remarkable photocatalytic degradation performance for oxytetracycline compared with that of pure Bi2WO6 nanosheets. The excellent photocatalytic activities of Bi2O3–Bi2WO6 composites could be attributed to the heterojunction structure and the oxygen vacancies caused by ultrathin structures.