Okasha Aly, Gomaa Fathia, Elhaes Hanan, Morsy Mohamed, El-Khodary Sherif, Fakhry Ahmed, Ibrahim Medhat
Spectroscopy Department, National Research Centre, 12311 Dokki, Cairo, Egypt.
Chemistry Department, Faculty of Women for Arts, Science and Education, Ain Shams University, 11757 Cairo, Egypt.
Spectrochim Acta A Mol Biomol Spectrosc. 2015 Feb 5;136 Pt B:504-9. doi: 10.1016/j.saa.2014.09.063. Epub 2014 Sep 30.
Nano titanium dioxide TiO2 was synthesized using hydrolysis method then subjected to several characterizations. XRD revealed that the as-prepared sample is pure anatase phase and after calcinations at 500°C for 3 h the crystallinity has increased. The crystallite size calculated by Debye-Scherrer's formula is 8 nm. The HRTEM image shows an average size of about 9 nm, which is close to the XRD calculation from Scherrer's formula. PM3 semiempirical quantum mechanical calculations were conducted to present the electronic as well as thermal properties for TiO2. FTIR spectra between 800 and 400 cm(-1) are the verification for the lattice vibrations of anatase TiO2. The photo catalytic degradation of methylene blue (MB) was tested by the prepared nano TiO2. Results indicate that, the maximum degradation efficiency reached 94.4% after 120 min of UV irradiation. This increase in the degradation efficiency of TiO2 could be attributed to the reduction in particle size that enhanced the crystallinity as a result of heat treatment.
采用水解法合成了纳米二氧化钛TiO₂，然后对其进行了多种表征。X射线衍射（XRD）表明，所制备的样品为纯锐钛矿相，在500℃煅烧3小时后结晶度增加。通过德拜-谢乐公式计算出的微晶尺寸为8纳米。高分辨率透射电子显微镜（HRTEM）图像显示平均尺寸约为9纳米，这与根据谢乐公式由XRD计算的结果相近。进行了PM3半经验量子力学计算以呈现TiO₂的电子和热性质。800至400厘米⁻¹之间的傅里叶变换红外光谱（FTIR）是锐钛矿TiO₂晶格振动的验证。用制备的纳米TiO₂测试了亚甲基蓝（MB）的光催化降解。结果表明，在紫外线照射120分钟后，最大降解效率达到94.4%。TiO₂降解效率的提高可归因于粒径的减小，而粒径减小是热处理导致结晶度提高的结果。
