碳、铈掺杂改性纳米TiO_2及其光催化性能研究

Study on C,Ce and C,Ce co-doped TiO_2 nanoparticles and their photocatalytic properties

文章介绍采用碳、铈对溶胶-凝胶法制备的纳米TiO2进行单掺杂、共掺杂修饰。研究结果显示,碳、铈的掺杂均有效地提高了TiO2对亚甲基蓝溶液的光催化活性,且碳-铈共掺杂存在协同效应,当共掺杂比例为n(Ce)∶n(C)∶n(Ti)=0.002∶0.3∶1时,催化剂的活性最高,对亚甲基蓝溶液的脱色率4 h可达64%;通过X射线衍射、紫外-可见漫反射吸收光谱等手段,对催化剂进行表征,结果显示,单掺杂及共掺杂催化剂中TiO2的晶型均为锐钛矿型,适量碳和(或)铈的掺杂均能有效减小TiO2的晶粒粒径;紫外可见漫反射光谱表征显示铈的掺杂使TiO2光催化剂的感光范围有明显红移,在可见光区吸收增强。

Ce doped and co-doped nano-TiO2 photocatalysts were prepared by the sol-gel method. The results showed that doping of C and Ce improved the photocatalytic activity of TiO2 in the decoloration of methyl blue under visible light and there existed synergic effect in co-doping. When the molar ratio among Ce, C and Ti was 0.002 ： 0.3 ： 1, the catalyst displayed the highest catalytic activity, and the decoloration degree of methyl blue reached 64 % after 4 h. The catalysts were characterized by Xray diffraction（XRD） and UV-vis diffuse reflectance spectra（UV-DRS）,and the results indicated that the crystalline phase of all doped TiO2 photocatalysts was anatase and the size of photocatalysts decreased after proper doping of C and/or Ce. UV-DRS showed that the band edge of Ce doped catalysts moved to longer wavelength obviously and the absorption in the visible range was strengthened.