可见光激发Pr^(3+)掺杂Y_2SiO_5/TiO_2膜对硝基苯的降解性能

Photocatalytic Performances of Pr^(3+) Doped Y_2SiO_5/TiO_2 Film for Nitrobenzene Degradation under Visible-light Irradiation

采用溶胶-凝胶法制备了Pr^(3+)掺杂上转换材料Y_2SiO_5(Pr^(3+):Y_2SiO_5)与TiO_2的复合材料,并以玻璃片(GS)和玻璃纤维滤膜(GFF)为载体,附载形成Pr^(3+):Y_2SiO_5/TiO_2复合膜。采用X射线衍射仪、扫描电子显微镜、荧光光谱仪和比表面积及孔径分析仪,对不同载体的Pr^(3+):Y_2SiO_5/TiO_2复合膜的结构性能进行了表征。以硝基苯为目标降解物,考察了薄膜中上转换材料Pr^(3+):Y_2SiO_5与TiO_2的最佳质量比和不同载体情况下复合膜的可见光催化性能。结果表明:Pr^(3+):Y_2SiO_5与TiO_2的最佳质量比为4%;GS复合膜和GFF复合膜对浓度为5 mg/L硝基苯溶液12h最佳降解率分别为80%和87%,重复使用4次后的降解率分别为58%和70%。GFF复合膜综合性能高于GS复合膜,前者对硝基苯在16h去除率可达97%,有机碳(TOC)去除率高达95%。

pr3＋-doped up-conversion materials Y2SiO5 （pr3＋：Y2SiOs） compotmded with TiO2 were prepared by a sol-gel method. The Pr3＋：Y2SiO5/TiO2 composite films were formed via impregnation of carriers of glass slide （GS） or glass fiber filter （GFF） into the sol. The structural properties of the Pr3＋：Y2SiOs/TiO2 composite films were characterized by X-ray diffraction, scanning electron microscopy, fluorescence spectroscopy and specific surface area/pore size analysis, respectively. The visible light catalytic properties of the pr3＋：YESiOs/TiO2 composite films prepared at optimum mass ratio of pr3＋：YzSiO5 to TiO2 and different supporters circumstances for the degradation of nitrobenzene solution were investigated. The results indicate that the optimal mass ratio of pr3＋：Y2SiO5 to TiO2 is 4%, the degradation rates of GS composite film and GFF composite film in 5 mg/L of nitrobenzene solution under visible light irradiation for 12 h are 80% and 87%, respectively. The degradation rates of these films after 4-time reuse are 58% and 70%, respectively. The GFF composite films present a superior visible light photocatalytic property, i.e., the degradation rate and total organic carbon （TOC） removal rate on nitrobenzene under light irradiation for 16 h are 97% and 95%, respectively, which is better than that of the GS composite films.