钨掺杂介孔TiO_2微球紫外光下降解罗丹明B的研究

Enhanced Photocatalytic Degradation of Rhodamine B under Ultraviolet Light Irradiation on Mesoporous Anatase TiO_2 Beads by Doping with W

以钛酸四异丙酯为钛源,钨酸铵为钨源,通过水热法制备了W掺杂介孔TiO_2微球.所得样品用X射线衍射(XRD)、扫描电镜(SEM)、氮吸附、紫外可见漫反射等测试方法表征.以罗丹明B为目标降解物,考察了钨掺杂介孔TiO_2在紫外光下对罗丹明B的催化活性.结果表明,TiO_2微球平均孔径10 nm左右.钨掺杂对TiO_2微球结构与晶型没有影响,但是缩小了二氧化钛的光吸收范围,适量掺杂钨离子后,TiO_2吸收边产生蓝移,吸收波长从384 nm缩短为378 nm.钛钨摩尔比为0.2%的钨掺杂TiO_2活性最好,对罗丹明B降解率较未掺杂TiO_2提高约30%.

Eesoporous anatase TiO2 beads were prepared via hydrothermal and calcination processes with additionof W source for doping W . All the samples were characterized by X-ray diffraction （ X R D ） , scanning electronmicroscopy （ S E M ） , nitrogen adsorption, and UV-visible（ UV-Vis） diffuse reflectance spectroscopy. R h B（rhodamine B ） aqueous solution is used as a target degradation to investigate the photocatalytic activity of theW doped mesoporous TiO2 beads. The doped mesoporous TiO2 beads achieves a relatively narrow pore size distributioncentered at 10. 0 nm. All the samples are of anatase phase,which implies no variation of crystal phasegeneration in the W-doping process. The band edge absorption blue shifts from 384 n m to 378 n m with a moderateamount of W doping. TiO2 beads have a higher photocatalytic activity when the mole ratio of Ti to W is 0. 2 % . Photocatalytic degradation of R h B on TiO2 ： W-0. 2at% is increased to 3 0 % of that on pure TiO2 beads.