Bi3.25Sm0.75Ti3O12纳米线的水热合成及可见光催化性能

摘要

Bi3.25Sm0.75Ti3O12 (BSmT) nanowires of 40 nm in diameter were synthesized through a one-step hydrothermal process.The BSmT nanowires are of layered perovskites.The results of UV-Visible diffuse reflectance spectra (DRS) demonstrate that the band gap of BSmT nanowires is about 2.67 eV.The BSmT nanowires exhibit higher photocatalytic activity than that of the traditional N doped TiO2 (N-TiO2) and pure bismuth titanate (Bi4Ti3O12,BIT).92.0％ methyl orange (MO) (0.01 mmol ·L-1) is decolorized after visible light irradiation for 360 min.The high photocatalytic performance of BSmT photocatalyst could be attributed to the strong visible light absorption and the recombination restraint of the e-/h+ pairs resulting from doping of Sm3+ ions.In addition,after 4 recycles,there is no significant decrease in the photocatalytic activity,indicating that BSmT is a stable photocatalyst for degradation of MO under visible light irradiation.%用一步水热法制备了直径约为40 nm的Bi3.25Sm0.75Ti3O12(BSmT)纳米线.BSmT纳米线为层状钙钛矿结构.紫外可见漫反射光谱表明,制备出的BSmT材料的带隙能约为2.67 eV.催化反应结果表明,BSmT的光催化活性比掺氮TiO2(N-TiO2)和纯相钛酸铋(Bi4Ti3O12,BIT)高得多,经可见光照射360 min,浓度为0.01 mmol.L-1甲基橙溶液的降解率可达到92.0％.BSmT光催化剂具有更高催化活性的原因是Sm3+离子掺杂拓展了BIT对可见光的吸收范围,同时抑制了BIT的光生电子-空穴的复合.并且BSmT光催化剂经循环使用4次后,其光催化活性并没有明显降低,表明BSmT是一种稳定有效的可见光催化剂.