| As a typical environmental endocrine disruptor(EDCs),17 α-ethynylestradiol(EE2)has the characteristics of persistent toxicity,potential hazard,bioaccumulation.It can be enriched through the food chain and gradually enlarged.It can get into the organism directly or indirectly,in which it has a long half-life and a serious threat to the normal life of the organism.Therefore,the exploration of new materials and methods for the treatment of EE2 has become a hot issue for environmental scientists.Photocatalytic degradation is a promising method for the treatment of EDCs.The surface wettability of photocatalyst has a very important effect on its catalytic efficiency,but it has not been paid much attention by researchers.Therefore,in this paper,the preparation of a few photocatalysts with controllable wettability were prepared and the influence of the surface wettability on the performance of photocatalyst were studied.The prepared photocatalysts with controllable wettability were applied to the visible light degradation of EE2,which showed significantly improved degradation rate of EE2.In this paper,Ag2 Mo O4/Bi VO4(AMO/BVO)and Ag I/Bi VO4 composite photocatalysts were prepared by hydrothermal precipitation method.Under the condition of water bath,hexamethyldisilazane(HMDS)and trimethylchlorosilane(TMCS),3-(Methacryloyloxy)propyltrimethoxysilane(KH-570),1H,1H,2H,2H-perfluorodecyltriethoxysilane(PFDS)were used to modify the surface of the two photocatalysts,respectively.XRD,XPS,SEM,UV-vis DRS,WCA,PL and TRF were used to study the phase composition,morphology,surface wettability and optical properties of the materials.The catalytic performance of the modified photocatalyst for EE2 under visible light irradiation was studied.The details are as follows:1.AMO/BVO composite was synthesized by hydrothermal precipitation method.The optimal conditions were determined by EE2 degradation experiments as follows: the solvothermal temperature was 200 ℃,the reaction time was 24 h,and the mass ratio of AMO/BVO was 30%.The surface of the optimized AMO/BVO composite was modified by HMDS at 70 ℃ in water bath.When 1.0 m L of HMDS was added to modified 0.5000 g of the optimized AMO/BVO composite,the static contact angle of the photocatalystsurface was 34.5°.When this modified photocatalyst(dose of 0.5 g/L)was applied to degrade the 3.0 mg/L EE2 solution,the removal rate was close to 100% after 40 min of visible light irradiation.The surface wettability of the composite was tuned by controlling the amount of HMDS.When the contact angle of the catalyst was controlled in the range of 19.0-44.0°,the photocatalytic performance was significantly improved,and the removal rate was higher than that of the unmodified AMO/BVO composite(70.4%),pure Bi VO4(9.1%)and pure Ag2 Mo O4(20.9%).2.Ag I/Bi VO4 composite was synthesized by hydrothermal precipitation method.Through the degradation experiment of EE2,the optimal conditions were determined as follows: the solvothermal reaction temperature was 140 ℃,the solvothermal reaction time was 16 h,and the mole ratio of Ag I/Bi VO4 was 1:1.The surface of the optimized Ag I/Bi VO4 composite was modified by TMCS,KH-570 and PFDS respectively at 70 ℃.When 1.3 m L of TMCS,2.0 m L of KH-570 and 0.05 m L of PFDS were used to modify 0.5000 g of the optimized Ag I/Bi VO4 composite,the WCA on the surface of the material was 48.1°,51.0° and 75.8° respectively.When this modified photocatalyst(dose of 0.5 g/L)was applied to degrade the 3.0 mg/L EE2 solution,the removal efficiency of EE2 was 99.4%,92.9% and 90.0% respectively under 20 min of visible light irradiation.The surface wettability of the photocatalysts could be obtained by controlling the amount of modifier.When the WCA of Ag I/Bi VO4 composite modified by TMCS,KH-570 and PFDS were tuned in the range of 42.0-54.7°,42.0-52.3°,68.3-75.8°,the removal rate of EE2 was significantly improved,which was significantly better than that of Ag I/Bi VO4 composite(74.7%)and pure BiVO4(8.4%). |
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