TiO_2基多组分纳米光催化剂的制备及其性能研究

Preparation and Photocatalytic Performance of TiO_2 Based Multi-Nanophotocatalyst

采用超声辅助的溶胶-凝胶(Sol-Gel)法制备了以β-分子筛为载体,Pr和H_3PMo_(12)O_(40)(PMo_(12))改性的多组分TiO_2光催化剂(ZPM-TiO_2),以X射线衍射(XRD)、X射线光电子能谱(XPS)、N_2-吸附脱附(BET,BJH)、透射电子显微镜(TEM)、紫外-可见光吸收光谱(UV-vis)等手段对催化剂的晶型结构、元素组成、形貌和光吸收特性等性能进行表征和分析。并且选择亚甲基蓝(MB)作为降解对象分别考察了ZPM-TiO_2的紫外和可见光催化活性。实验结果表明:与ZP-TiO_2和ZM-TiO_2相比,ZPM-TiO_2表现出优异的紫外和可见光光催化性能,主要是由于PMo_(12)和Pr的加入可以有效抑制光生电子空穴对的复合,从而提高其光催化活性。催化剂循环使用实验表明,ZPM-TiO_2经5次重复使用后,MB的降解率仍可达85%,ZPM-TiO_2具有较好的循环使用稳定性。

TiO_2mluti-naocatalysts modified by Pr and H_3PMo_（12）O_（40）（PMo_（12）） were fabricated via a facile ultrasonic assistant deposition-precipitation method using β-zeolite as a carrier. The X-ray diffraction（ XRD）,X-ray photoelectron spectroscopy（ XPS）,nitrogen adsorption-desorption analysis（ BET and BJH）,transmission electron microscopy（ TEM） and ultraviolet-visible light absorption spectra analysis（ UV-vis） were used to characterize the structure,morphology and optical properties of the as-prepared photocatalysts. The fabricated photocatalysts were employed to degrade methylene blue（ MB） under UV and visible light irradiation in aqueous phase. A remarkably enhanced photocatalytic degradation efficiency of ZPM-TiO_2 nanocomposites was observed when compared to that of ZP-TiO_2 and ZM-TiO_2,the possible reason is adding of Pr^（3 ＋）and PMo_（12） can inhibit the recombination of the photogeneration electron and hole,which can enhance the photocatalytic performance efficiency. The stability of ZPMTiO_2 photocatalyst was also evaluated by repeatedly performing 5 times of the MB degradation experiments using same catalyst. The results showed that gradually decreased MB degradation efficiencies from 100 to 85% was obtained from the first to fifth reuse cycles of the photocatalyst. Above all,the prepared photocatalyst ZPM-TiO_2 has shown excellent photocatalytic performance and stability.