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

Abstract

In our work, we have successfully synthesized WO 3 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 WO 3 nanosheets is discussed in this study based on the experimental results and our understanding. WO 3 nanosheets modified with Pt exhibit enhanced photocatalytic activity of tetracycline compared with bare WO 3 nanosheets under visible-light irradiation (λ > 420 nm). Furthermore, the effects of Pt as cocatalyst can be clearly drawn, and the degradation ratio of 2% Pt/WO 3 nanosheets is over 3 times that of bare WO 3 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/WO 3 photocatalysts, further indicating the ·OH radicals do exist in the process of the photocatalytic oxidation (PCO) of TC.