Chang Pei-Yi, Huang Chun-Hsin, Doong Ruey-An
Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan.
Water Sci Technol. 2009;59(3):523-30. doi: 10.2166/wst.2009.004.
The vanadium (V)-doped mesoporous titanium dioxide (TiO(2)) nanoparticles with V/Ti ratios from 0-2 wt% were prepared using sol-gel method in the presence of triblock polymers, Pluronic F127. SEM images showed that the V-doped TiO(2) nanoparticles were porous structures. The surface areas and pore sizes were in the range 85-107 m(2)/g and 12-14 nm, respectively. From XRPD, the V-doped mesoporous TiO(2) after calcination at 500 degrees C was mainly anatase phase, and the crystallite sizes were in the range 14-16 nm. TEM images showed that vanadia was doped both on the surface and in the lattice of anatase TiO(2). A slight red-shift in wavelength absorption was observed when V/Ti ratio increased from 0 to 2 wt%. Addition of vanadium ion slightly decreased the photocatalytic activity of TiO(2) toward the decolorization of MB under the illumination of UV light at 305 nm. However, a 1.6-1.8 times increase in rate constants for MB photodegradation was observed when 0.5-1.0 wt% V-doped TiO(2) was illumined by solar simulator at AM 1.5. These results demonstrated that the doping of low concentrations of V ion into mesoporous TiO(2) enhance the photocatalytic activity of mesoporous TiO(2) towards photodecomposition of azo dye in the visible range.
采用溶胶 - 凝胶法，在三嵌段聚合物Pluronic F127存在的条件下制备了钒（V）掺杂量（V/Ti比）为0 - 2 wt%的介孔二氧化钛（TiO₂）纳米颗粒。扫描电子显微镜（SEM）图像显示，钒掺杂的TiO₂纳米颗粒为多孔结构。其比表面积和孔径分别在85 - 107 m²/g和12 - 14 nm范围内。X射线粉末衍射（XRPD）结果表明，500℃煅烧后的钒掺杂介孔TiO₂主要为锐钛矿相，微晶尺寸在14 - 16 nm范围内。透射电子显微镜（TEM）图像显示，氧化钒既掺杂在锐钛矿TiO₂的表面，也掺杂在其晶格中。当V/Ti比从0增加到2 wt%时，观察到波长吸收有轻微的红移。在305 nm紫外光照射下，钒离子的加入略微降低了TiO₂对亚甲基蓝（MB）脱色的光催化活性。然而，当0.5 - 1.0 wt%的钒掺杂TiO₂在AM 1.5太阳光模拟器照射下时，观察到MB光降解的速率常数增加了1.6 - 1.8倍。这些结果表明，向介孔TiO₂中掺杂低浓度的钒离子可增强介孔TiO₂在可见光范围内对偶氮染料光分解的光催化活性。
