Excellent photocatalysis of Bi2WO6 structured with oxygen vacancies in degradation of tetracycline

Photocatalysis is a green, efficient and clean pollutant degradation technology. In this work, a novel Bi2WO6 photocatalytic material with oxygen vacancies was synthesized by a simple solvothermal method using ethylene glycol and ethanol as solvents. Tetracycline, as typical antibiotic organic pollutant, was selected to evaluate the photocatalytic activity of the prepared photocatalyst. The prepared oxygen-deficient Bi2WO6 material has good photocatalytic activity under visible light irradiation. The results showed that the oxygen-deficient Bi2WO6 was regular microsphere in shape with narrower and more uniform pore size distribution than Bi2WO6. Moreover, when visible light irradiation was lasted for 180 min, the degradation rate of tetracycline reached 79.68%, showing a higher degradation rate compared with that of Bi2WO6. Furthermore, after four cycles, the degradation rate of tetracycline could still reach 68.64%. This was due to the oxygen vacancies significantly enhanced the photocatalytic activity of Bi2WO6. In addition, as shown by the UV–Vis DRS analysis, the presence of oxygen vacancies enhances the utilization of visible light by Bi2WO6, and reduces the band gap of Bi2WO6. This study will provide an innovative idea for the construction of oxygen-deficient photocatalysts for water treatment.