不同氮源溶剂热合成N-TiO_2纳米颗粒及其光催化降解气相苯(英文)

Solvothermal synthesis of N-doped TiO_2 nanoparticles using different nitrogen sources, and their photocatalytic activity for degradation of benzene

采用三种不同的氮源溶剂热合成了锐钛矿-板钛矿混晶的N-TiO2催化剂.采用X射线衍射、N2吸附-脱附、X射线光电子能谱和透射电子显微镜等手段对催化剂进行了表征.重点研究了不同氮源对催化剂的相组成、晶粒尺寸、微观结构以及比表面积的影响.采用紫外光降解气相苯测试了合成材料的催化活性.结果表明,以水合肼为氮源合成的N-TiO2表现出最优的光催化活性,其活性明显高于P25,且能够循环使用15次以上.采用气相色谱-质谱技术分析了光降解过程的中间产物,基于此提出了相应的降解机理.

Anatase-brookite mixed-phase N-doped TiO2 (N-TiO2) nanoparticles were synthesized through a solvothermal method using different nitrogen sources. The resulting samples were characterized by X-ray diffraction, specific surface area measurement, X-ray photoelectron spectroscopy, and stand-ard and high-resolution transmission electron microscopy. The effects of the different nitrogen sources on phase composition, particle size, microstructure, and specific surface area are investi-gated. The photocatalytic activity of the TiO2 samples was evaluated through photocatalytic degra-dation of gaseous benzene under UV-light irradiation. N-TiO2 prepared using hydrazine hydrate achieved the highest photocatalytic performance in all the samples studied (including the commer-cial P25). Different intermediates during the photocatalytic degradation of benzene over HNT were identified by GC-MS analysis. A detailed reaction mechanism was proposed to explain their for-mation as intermediates in the reaction. Moreover, the photocatalytic activity of the nanoparticles remained almost unchanged after 15 gaseous-benzene degradation test cycles.