金属共掺杂纳米TiO_2对甲基橙的催化降解

Influence of nano TiO_2 by metal co-doping on photocatalytic degradation to methyl orange

以硫酸钛、CoCl2·6H2O和FeCl3为原料,采用共沉淀法制备了掺杂不同量Co2+和Fe3+的TiO2纳米粒,通过X-射线衍射(XRD)、差热-热重(TG-DTA)和紫外-可见吸收光谱(UV-Vis)等分析手段对样品的晶体类型、光谱吸收特征进行了表征。结果表明,金属共掺杂TiO2纳米粒仍以锐钛矿相存在,粒子的粒径约为12nm;Co2+和Fe3+掺入TiO2后,主要以替代的方式占据TiO2晶格中Ti4+的位置,并在TiO2禁带中产生掺杂能级,使原来位于380nm的吸收带边红移至460nm。以太阳光为光源,当Co2+掺杂量为0.025%,Fe3+掺杂量小于0.05%时,光催化剂TiO2的活性较高,对甲基橙的降解率接近100%。

Co^2＋ and Fe^3＋ doped TiO2 nanoparticles were prepared by co-precipitation method from Ti（SO4）2,CoCl2·6H2O and FeCl3, The crystal types and the property of absorption spectrum of TiO2 were examined by XRD, TG-DTA, UV-Vis etc. The resuits indicate that the diameter of Cox -Fey-TiO2 particle was 12 nm, the crystal phase was anatase, the doped Co^2＋ and Fe^3＋ ions can mainly penetrate into the lattice of TiO2 and substitute the Ti4. ions of TiO2. And then a doping energy level emerges among the gap of TiO2, which help to increase the visible light absorption of TiO2. The original absorption edge （about 380nm） of TiO2 moves to the longer wave （about 460 nm）. By sun＇s rays as light source, the activity of photocatalysts TiO2 is higher, and the degradation efficiency of methyl orange is about 100% under the condition of doping amount of Co2. 0. 025% and doping amount of Fe^3＋ less than 0.05%.