超声条件下制备氮掺杂TiO2及其光催化活性研究

为拓展二氧化钛对可见光的响应,超声条件下采用溶胶凝胶法以三乙胺为氮源制备出N掺杂的纳米TiO2光催化剂;以甲基橙的光催化降解为探针反应,评价其光催化活性;运用XRD、TEM、XPS和UV-Vis DRS等技术考察了超声及N掺杂对TiO2微晶尺寸、晶体结构、表面组成与光学性能的影响.结果表明,所制备N掺杂TiO2为纯锐钛矿型,超声抑制了光催化剂粒晶的增大,减弱了颗粒间的硬团聚;N掺杂使TiO2光谱响应波长拓宽至可见光区,有效改善了TiO2的可见光活性,对甲基橙溶液的降解速率比纯TiO2提高了69.9%.

Ultrasonic Preparation of Nitrogen-doped TiO2 and Its Photocatalytic Activities

In order to expand the optical response of titania into the visible-light region,nitrogen-doped TiO2 in anatase form were prepared by sol-gel method using triethylamine as nitrogen raw material under ultrasonic irradiation.The photocatalytic decomposition of methyl orange in aqueous solution was used as a probe reaction to evaluate their photocatalytic activities.The effects of ultrasonication and N doping on the crystallite sizes,crystal pattern,surface composition and optical property of the catalysts were investigated by means of the techniques such as XRD,TEM,XPS and UV-Vis DRS.The results show that nitrogen-doped TiO2 were anatase,ultrasonication does not only reduce the crystallite size but also enhances the hydrolysis of titanium alkoxide for faster and better crystallization of anatase nanoparticles.The doping of nitrogen could extend the absorption shoulder into the visible light region,resulting in significant improvement to the photoreactivity of nitrogen-doped TiO2.The apparent decomposition rate of Nitrogen-doped TiO2 is 1.699 times higher than that of pure TiO2 under visible light.