【摘要】 采用低温燃烧合成法制备了Ni掺杂TiO2光催化剂,通过紫外-可见漫反射光谱(UV-Vis DRS)、X射线粉末衍射(XRD)、激光散射、热重-差示扫描量热分析(TG-DSC)等方法对催化剂的光吸收特性、晶相组成、粒度分布、升温过程中化学变化等进行了表征,以亚甲基蓝为模型污染物考察了催化剂在可见光下的光催化活性.结果表明,相对P25而言,Ni掺杂TiO2的光吸收带边红移,当Ni/Ti原子比为0.4时,催化剂的带隙宽度为2.3eV,对应的吸收带边为564nm;催化剂晶型以锐钛矿TiO2为主,随Ni掺杂量增大,NiTiO3比例升高;催化剂粒径主要分布在50~150nm之间,占总量的96.9%;升温过程中催化剂在445.2℃发生晶型转化,出现锐钛矿和NiTiO3晶体.催化剂显示出较高的催化活性,在可见光作用150min后最高可使93.9%的亚甲基蓝分解,活性高于P25.更多还原

【Abstract】 Ni-doped TiO₂ photocatalysts were prepared by low temperature combustion synthesis and some properties,such as optical absorption,crystal type,grain size distribution and chemistry transformation during temperature rising were characterized by UV-Vis DRS,X-ray diffraction（XRD）,laser light dispersion grain size measurement machine and TG-DSC respectively.The photocatalytic activities of the prepared photocatalysts under visible light irradiation were evaluated by monitoring the degradation of methylene blue dye,a probe pollutant.The results indicate that the Ni-doped TiO₂ photocatalysts prepared by low temperature combustion synthesis shift the optical absorption threshold to visible light,the band gap of 0.4 Ni-TiO₂（atomic ratio） is 2.3 eV,which corresponds to a 564nm threshold in the visible light range.The crystal type of photocatalyst is anatase TiO₂ and the content of NiTiO₃ rise with the increase of Ni dopant.The grain size of photocatalyst distributes from 50 to 150nm,which account for 96.9% of entire quantity.During temperature rising,the TiO₂ phase in photocatalyst transforms from amorphous structure to anatase and NiTiO₃ crystallites appear at 445.2℃.After 150min visible light irradiation,93.9% of methylene blue dye are degraded over 0.4 Ni-TiO₂ photocatalyst.The photocatalytic activity of Ni doped TiO₂ is higher than that of P25 under identical conditions.更多还原