Kuvarega Alex T, Krause Rui W M, Mamba Bhekie B
UJ Centre for Nanomaterials Science, Department of Applied Chemistry, University of Johannesburg, PO Box 17011, Doornfontein 2028, Johannesburg, South Africa.
J Nanosci Nanotechnol. 2013 Jul;13(7):5017-27. doi: 10.1166/jnn.2013.7589.
Nitrogen, osmium co-doped TiO2 photocatalysts were prepared by a modified sol-gel method using ammonia as the nitrogen source and osmium tetroxide as the source of osmium. The role of rutile phase OsO2 in enhancing the photocatalytic activity of rutile TiO2 towards the degradation of Eosin Yellow was investigated. The materials were characterised by various techniques that include FTIR, Raman, XRD, SEM, EDS, TEM, TGA and DRUV-Vis. The amorphous, oven dried sample was transformed to the anatase and then the rutile phase with increasing calcination temperature. DRUV-Vis analysis revealed a red shift in absorption with increasing calcination temperature, confirmed by a decrease in the band gap of the material. The photocatalytic activity of N, Os co-doped TiO2 was evaluated using eosin yellow degradation and activity increased with increase in calcination temperature under simulated solar irradiation. The rutile phase of the co-doped TiO2 was found to be more effective in degrading the dye (k(a) = 1.84 x 10(-2) min(-1)) compared to the anatase co-doped phase (k(a) = 9.90 x 10(-3) min(-1)). The enhanced photocatalytic activity was ascribed to the synergistic effects of rutile TiO2 and rutile OsO2 in the N, Os co-doped TiO2.
采用改进的溶胶 - 凝胶法，以氨为氮源、四氧化锇为锇源制备了氮、锇共掺杂的二氧化钛光催化剂。研究了金红石相OsO₂在增强金红石型TiO₂对曙红Y降解的光催化活性中的作用。通过傅里叶变换红外光谱（FTIR）、拉曼光谱、X射线衍射（XRD）、扫描电子显微镜（SEM）、能谱分析（EDS）、透射电子显微镜（TEM）、热重分析（TGA）和漫反射紫外 - 可见光谱（DRUV - Vis）等多种技术对材料进行了表征。随着煅烧温度升高，无定形的烘干样品先转变为锐钛矿相，然后转变为金红石相。DRUV - Vis分析表明，随着煅烧温度升高，吸收发生红移，这由材料带隙的减小得到证实。在模拟太阳光照射下，通过曙红Y降解评估了氮、锇共掺杂TiO₂的光催化活性，其活性随煅烧温度升高而增加。发现共掺杂TiO₂的金红石相比锐钛矿共掺杂相在降解染料方面更有效（金红石相k(a) = 1.84 x 10⁻² min⁻¹，锐钛矿相k(a) = 9.90 x 10⁻³ min⁻¹）。光催化活性的增强归因于氮、锇共掺杂TiO₂中金红石型TiO₂和金红石相OsO₂的协同效应。
