爆温对气相爆轰合成纳米TiO2结构和性能的影响

采用气相爆轰法制备纳米TiO₂粉末, 并研究爆温对样品的结构和性能的影响。使用XRD、TEM及甲基橙溶液降解来表征样品的结构与性能。结果表明: 爆温对样品中金红石相含量有一定影响,在爆温为2524 K时, 金红石相含量达到最大值92.2%; 爆温对样品的平均粒径有重大影响, 爆温与样品的平均粒径呈线性关系, 爆温越高, 样品的平均粒径越大,当爆温由2399 K提高到3114 K时,平均粒径由87.2 nm提高到172.9 nm; 爆温对样品的光催化性有着间接影响, 爆温越高, 样品的平均粒径越大, 光催化效能降低。当爆温为2399 K时, 制备样品的平均粒径为87.24 nm, 锐钛矿比例为31.7%, 光催化活性最高, 在紫外光下40 min甲基橙溶液降解率为90.82%, 反应速率常数k为0.062。

Influence of Explosion Temperature on Structure and Property of Nano-TiO2 Prepared by Gaseous Detonation Method

TiO₂ powders were fabricated by gaseous detonation method, and influences of explosion temperature on phase composition, crystallite size and photocatalytic property of TiO₂ were studied. The prepared samples were characterization by X-ray diffraction (XRD) and transmission electron microscope (TEM). Photocatalytic performance was determined by degradation of methyl orange dye under UV irradiation. The results show that explosion temperature has a significant effect on mean particle size and weight fraction of rutile in the sampls. The maximum percent content of rutile is 92.2% when explosion temperature is 2524 K. The average particle size has linear relationship with explosion temperature, and the sample particle sizes increase from 87.2 nm to 172.9 nm with explosion temperature increasing from 2399 K to 3114 K. Explosion temperature exerts an indirect influence on photocatalytic performance. Photocatalytic performance decreases with explosion temperature increment. At 2399 K, the sample exerts the highest photocatalytic activity that the degradation rate of methyl orange solution can achieve 90.82% under UV light for 40 min, and the fraction of anatase and mean particle size is 31.7% and 87.24 nm, respectively.