Nagaveni K, Hegde M S, Ravishankar N, Subbanna G N, Madras Giridhar
Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore-560012, India.
Langmuir. 2004 Mar 30;20(7):2900-7. doi: 10.1021/la035777v.
Nanocrystalline TiO2 was synthesized by the solution combustion method using titanyl nitrate and various fuels such as glycine, hexamethylenetetramine, and oxalyldihydrazide. These catalysts are active under visible light, have optical absorption wavelengths below 600 nm, and show superior photocatalytic activity for the degradation of methylene blue and phenol under UV and solar conditions compared to commercial TiO2, Degussa P-25. The higher photocatalytic activity is attributed to the structure of the catalyst. Various studies such as X-ray diffraction, Raman spectroscopy, Brunauer-Emmett-Teller surface area, thermogravimetric-differential thermal analysis, FT-IR spectroscopy, NMR, UV-vis spectroscopy, and surface acidity measurements were conducted. It was concluded that the primary factor for the enhanced activity of combustion-synthesized catalyst is a larger amount of surface hydroxyl groups and a lowered band gap. The lower band gap can be attributed to the carbon inclusion into the TiO2 giving TiO(2-2x)C(x) VO2**.
采用硝酸氧钛和各种燃料（如甘氨酸、六亚甲基四胺和草酰二肼）通过溶液燃烧法合成了纳米晶TiO₂。这些催化剂在可见光下具有活性，光吸收波长低于600 nm，并且与商用TiO₂德固赛P-25相比，在紫外光和太阳光条件下对亚甲基蓝和苯酚的降解表现出优异的光催化活性。较高的光催化活性归因于催化剂的结构。进行了各种研究，如X射线衍射、拉曼光谱、布鲁诺尔-埃米特-泰勒表面积、热重-差热分析、傅里叶变换红外光谱、核磁共振、紫外-可见光谱和表面酸度测量。得出的结论是，燃烧合成催化剂活性增强的主要因素是大量的表面羟基和降低的带隙。较低的带隙可归因于碳掺入TiO₂中形成TiO(2 - 2x)C(x) VO₂** 。
