掺铁纳米TiO_2的制备及其光催化性能

以TiC l4为原料,采用微波加热与常规加热2步合成法制备掺铁纳米TiO2。用X射线粉末衍射(XRD)、透射电镜(TEM)、紫外可见吸收光谱(UV-V is)、光电子能谱(XPS)等测试技术对其进行了表征。结果表明,所制得的掺铁纳米TiO2是以锐钛矿为主相的混晶,平均粒径约为10 nm,适量Fe3+的掺杂能促进金红石相变,抑制锐钛矿晶粒的生长,使Ti2p电子结合能升高0.3 eV,并使TiO2吸光能力增强,带边吸收向可见光区移动。在UVA段(320~400 nm)光照下,通过对维生素VB12的光催化降解,发现掺入摩尔分数为0.5%的Fe3+的纳米TiO2能明显提高其光催化活性,使维生素B12的降解速率提高2.3倍。

Preparation and Photocatalytic Property of Iron-doped TiO_2 Nanoparticles

A series of iron-doped nano-titania were prepared from titanium tetrachloride precursor via a two-step method involving microwave and conventional heating treatments.The iron-doped nano-titania was characterized with XRD,TEM,UV-Vis and XPS techniques.The results indicated that the iron-doped nano-titania with an average diameter of 10 nm contained anatase as the main phase and rutile phase.It was found that the ferric ion dopant of a proper concentration promoted the formation of the rutile phase,and reduced the crystallite size of anatase.An increase of 0.3 eV in the binding energy of Ti_(2p) was observed after the nano-titania was doped with 0.5%(mole fraction) ferric ions.Moreover,the photoresponse shifted to the visible region for(iron-)doped nano-titania.Photocatalytic activity was evaluated by measuring the decomposition rates of vitamin B_(12) exposed to UVA(320~400) radiation.The results indicated that the optimum mole fraction of ferric ions was 0.5% for the iron-doped nano-titania,which doubled the photocatalytic decomposition rate of vitamin B_(12) compared to that of undoped nano-titania.