Liu Chao, Tang Xin-Hu, Mo Ce-Hui, Wang Jun
Department of Environmental Engineering, Jinan University, Guangzhou 510632, China.
Huan Jing Ke Xue. 2006 Nov;27(11):2150-3.
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 564 nm 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 degrees C. After 150 min 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.
采用低温燃烧合成法制备了镍掺杂二氧化钛光催化剂，并分别通过紫外可见漫反射光谱（UV-Vis DRS）、X射线衍射（XRD）、激光粒度分析仪和热重-差示扫描量热仪（TG-DSC）对其光吸收、晶体类型、粒径分布以及升温过程中的化学转变等性质进行了表征。通过监测作为探针污染物的亚甲基蓝染料的降解情况，对所制备的光催化剂在可见光照射下的光催化活性进行了评价。结果表明，低温燃烧合成法制备的镍掺杂二氧化钛光催化剂将光吸收阈值移至可见光区域，原子比为0.4的镍-二氧化钛的带隙为2.3 eV，这对应于可见光范围内564 nm的阈值。光催化剂的晶体类型为锐钛矿型二氧化钛，并且随着镍掺杂量的增加，钛酸镍的含量升高。光催化剂的粒径分布在50至150 nm之间，占总量的96.9%。在升温过程中，光催化剂中的二氧化钛相从无定形结构转变为锐钛矿型，并且在445.2℃时出现钛酸镍微晶。在可见光照射150分钟后，0.4镍-二氧化钛光催化剂上93.9%的亚甲基蓝染料被降解。在相同条件下，镍掺杂二氧化钛的光催化活性高于P25。
