Environmental Science Research Institution, Huazhong University of Science and Technology, No 1037 Luoyu Road, Wuhan 430074, PR China.
J Hazard Mater. 2010 May 15;177(1-3):639-47. doi: 10.1016/j.jhazmat.2009.12.080. Epub 2009 Dec 24.
Silver-modified TiO(2) (Ag-TiO(2)) with various Ag/Ti molar ratios were prepared by the microwave-assisted method and characterized by X-ray diffraction (XRD), transmission electron microscope (TEM) and UV-vis diffuse reflectance spectroscopy (UV-vis-DRS). Compared with the hydrothermal method, Ag-TiO(2) of small crystallite size and high crystallinity can be obtained by the microwave-assisted preparation method. When the Ag/Ti molar ratio increased from 0 to 2%, the doping of Ag promoted the phase transformation and inhibited the growth of anatase crystallite. The absorption edge of Ag-TiO(2) shifted to longer wavelength, and the band gap energy of Ag-TiO(2) decreased. However, after increasing the molar ratio Ag/Ti further from 2 to 4%, the anatase content, the crystallite size and the band gap energy of Ag-TiO(2) only increased slightly. In photodegradation gaseous toluene, the photocatalytic activity of Ag-TiO(2) increased with the increase of Ag/Ti molar ratio from 0 to 1%, but declined with the further increase to 2%. The optimal Ag/Ti molar ratio for photocatalytic activity of Ag-TiO(2) was found as 1%, with the content of anatase, rutile and brookite of 71.1, 14.5 and 14.4%, respectively. Compared with TiO(2), Ag-TiO(2) exhibited a better photostability in toluene degradation.
采用微波辅助法制备了不同 Ag/Ti 摩尔比的银修饰 TiO2（Ag-TiO2），并用 X 射线衍射（XRD）、透射电子显微镜（TEM）和紫外-可见漫反射光谱（UV-vis-DRS）进行了表征。与水热法相比，微波辅助制备法可得到晶粒尺寸较小、结晶度较高的 Ag-TiO2。当 Ag/Ti 摩尔比从 0 增加到 2%时，Ag 的掺杂促进了相转变并抑制了锐钛矿晶的生长。Ag-TiO2 的吸收边缘向长波长移动，带隙能降低。然而，当 Ag/Ti 摩尔比进一步从 2%增加到 4%时，Ag-TiO2 的锐钛矿含量、晶粒尺寸和带隙能仅略有增加。在光降解气态甲苯中，Ag-TiO2 的光催化活性随 Ag/Ti 摩尔比从 0 增加到 1%而增加，但进一步增加到 2%时则下降。发现 Ag-TiO2 的最佳光催化活性的 Ag/Ti 摩尔比为 1%，其锐钛矿、金红石和板钛矿的含量分别为 71.1%、14.5%和 14.4%。与 TiO2 相比，Ag-TiO2 在甲苯降解中表现出更好的光稳定性。
