高活性TiO_2纳米晶的酸催化Sol-Gel法制备与表征

Preparation and Characterization of TiO_2 Nanocrystals with High Photocatalytic Activity by an Acid-catalyzed Sol-Gel Method

采用酸催化的溶胶-凝胶法制备出了纳米TiO2光催化剂,以甲基橙的光催化降解为探针反应,评价了其光催化活性.运用XRD、TEM、FT-IR以及PL光谱技术对纳米TiO2的微晶尺寸、晶体结构、表面组成和性能进行表征.结果表明,400℃焙烧的TiO2纳米粒子的颗粒形貌为近球形,晶粒尺寸为11.69nm,样品分散性良好的锐钛矿型结构.在光催化降解甲基橙的实验中,400℃焙烧的TiO2纳米粒子表现出最高的光催化活性,这与表征结果一致.此外,550℃和650℃焙烧的具有锐钛矿型和金红石型混晶结构的TiO2纳米粒子,无混晶协同促进效应.

TiO2 nanoparticles with high photocatalytic activity for methyl orange degradation were prepared by an acid-catalyzed sol-gel method. The prepared samples on the crystallite sizes, crystal structure, surface composition, and optical property were characterized by means of XRD, TEM, FF-IR, and PL spectra. The results show that the crystallite size of anatase TiO2 calcined at 400 22 is about 11.69 nm and its morphology is approximate sphericity and has a better dispersivity. TiO2 calcined at 400 22 exhibits the highest photocatalytic activity in the experiments of the photocatalytic degradation of methyl orange, which is consistent with the results of characterization. Moreover, TiO2 composed of the coexistence of anatase and rutile calcined at 550 22 and 650 22 don＇t show a mixed-crystalline synergistic effect.