Organic Additives-Free Hydrothermal Synthesis and Visible-Light-Driven Photodegradation of Tetracycline of WO3 Nanosheets

In our work, we have successfully synthesized WO3 nanosheets via a simple, fast, and organic additives-free hydrothermal method. The obtained products are 200-500 nm-sized with square corners and high crystallinity. A possible formation mechanism of WO3 nanosheets is discussed in this study based on the experimental results and our understanding. WO3 nanosheets modified with Pt exhibit enhanced photocatalytic activity of tetracycline compared with bare WO3 nanosheets under visible-light irradiation (lambda > 420 nm). Furthermore, the effects of Pt as cocatalyst can be clearly drawn, and the degradation ratio of 2% Pt/WO3 nanosheets is over 3 times that of bare WO3 nanosheets, which is reasonable to expect the obvious Pt-dependent activity. The addition of 10 mL of iso-propanol leads to a considerable decreased degradation ratio (DR) of tetracycline (TC) on 2% Pt/WO3 photocatalysts, further indicating the center dot OH radicals do exist in the process of the photocatalytic oxidation (PCO) of TC.