V掺杂TiO2纳米粒子的制备及其光催化研究

摘要

5at.%V doped TiO2 and pure TiO2 nanoparticles were synthesized throug the sol-gel method and calcined at 500 ℃ for 6 h. XRD pattens showed that both samples were anatase TiO2 with some amorphous and crystal sizes were 6. 8 nm and 9. 7 nm, respectively. TEM images showed that nanoparticle sizes were in the ranges of 8. 0~18. 7 nm and 21. 6~30. 2 nm for V doped TiO2 and pure TiO2 , respectively, larger than the values calculated from the XRD patterns, due to the poor dispersion of TiO2 samples. EDS measurement confirmed the presence of V elements with a 6. 5at.%, also supported by IR spectrum. Raman spectrum confirmed the well dispersions of V elements in the TiO2 matrix. The photodegradation of Rh. B showed that the photodegradation efficiency of V doped TiO2 was lower than that of pure TiO2 , probably due to the enhancement of electron-hole pair recombination rate resulted from the high doping level.%溶胶-凝胶法制备5at.％V掺杂的TiO2和纯TiO2,然后在500℃煅烧6 h。 XRD谱图显示,样品均是锐钛矿型TiO2,还有一些无定型成分,平均晶粒大小分别为6.8 nm和9.7 nm。 TEM照片显示的纳米粒子大小分别在8.0~18.7 nm和21.6~30.2 nm范围内,比XRD计算结果大,这是因为样品未能充分分散所造成。 EDS谱图显示V的掺杂量是6.5at.％,红外光谱也证实V元素的存在。拉曼光谱表明, V元素均匀地分散在TiO2中。 Rh. B的光催化降解实验表明, V掺杂TiO2的光催化效率比纯TiO2低,这是由于较高的掺杂浓度导致电子-空穴复合中心增加,从而降低光催化效率。