Effect of the wettability of Ag2MoO4/BiVO4 {010} composite on the photocatalytic degradation for 17α-ethinyl estradiol

Abstract

To contribute to the wettability of bismuth vanadate (BiVO4) and indicate and improve the efficiency of 17α-ethinyl estradiol (EE2) removal, an Ag2MoO4/BiVO4 {010} composite photocatalyst was prepared in this study. By exposing the {010} crystal facet of BiVO4, its photocatalytic activity was improved. The surface of the photocatalyst was modified with hexamethyldisilazane (HMDS) to increase the surface water contact angle (WCA) of the material, indicating the relationship between the range of WCA of the photocatalyst surface and the performance of the photocatalytic degradation of EE2. The WCA of the HMDS-modified Ag2MoO4/BiVO4 {010} composite was increased from 14.2° to 47.0°, and the photocatalytic properties were significantly improved in the range of 19.1°− 44.0° for WCA. In addition, when the WCA of the Ag2MoO4/BiVO4 {010} composite reached 34.5°, the EE2 exhibited complete degradation in 40 min under the condition of visible light photocatalysis. This result obtained using the prepared composite was significantly better than those obtained using pure BiVO4 {010} (9.1%), pure Ag2MoO4 (20.9%), and unmodified Ag2MoO4/BiVO4 {010} composite (70.4%). The results showed that an effective way to improve photocatalytic performance is by controlling the WCA of the photocatalyst.