Flower-like Ag2WO4/CeO2 heterojunctions with oxygen vacancies and expedited charge carrier separation boost the photocatalytic degradation of dyes and drugs†
Charge carrier separation is a very important factor in photocatalysis, and it may be achieved through a variety of paths including the construction of heterojunctions and the formation of surface defects. Herein, we demonstrate the construction of flower-like Ag2WO4/CeO2 heterojunctions (namely ACs) by in situ deposition of Ag2WO4 on the surface of flower-like CeO2 with oxygen defects. The ACs with 2.3%, 3.8%, and 5.3% Ag2WO4 are defined as AC-1, AC-2, and AC-3, respectively, and we compare their photocatalytic removal efficiencies. Under visible light, AC-2 exhibits the highest photocatalytic removal efficiency toward cationic dye RhB and tetracycline (TC). The K value of AC-2 toward RhB degradation is determined to be 0.059 min−1, which is 7.56 and 8.94-fold higher than those of Ag2WO4 (0.0078 min−1) and CeO2 (0.0066 min−1), respectively. Moreover, the K value of AC-2 toward TC degradation (0.021 min−1) is 4.04 and 5.68-fold higher than those of Ag2WO4 (0.0052 min−1) and CeO2 (0.0037 min−1), respectively. Our results clearly demonstrate that the introduction of Ag2WO4 particles stimulates the formation of surface defects of CeO2, improves the visible light absorption, accelerates the charge carrier separation, and consequently boosts the photocatalytic degradation of dyes and drugs.