Synthesis and structure of nanocrystalline TiO2 with lower band gap showing high photocatalytic activity
Synthesis and structure of nanocrystalline TiO2 with lower band gap showing high photocatalytic activity
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DOI：
10.1021/la035777v
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发表时间：
2004-03-30
期刊：
影响因子：
3.9
通讯作者：
Madras, G
中科院分区：
文献类型：
--
作者：
Nagaveni, K;Hegde, MS;Madras, G
以硝酸钛和甘氨酸、六亚甲基四胺、草酰二肼等多种燃料为原料，采用溶液燃烧法合成纳米TiO2。这些催化剂在可见光下具有活性，光吸收波长在600 nm以下，与商品TiO2， Degussa P-25相比，在紫外和日光条件下对亚甲基蓝和苯酚的降解表现出优越的光催化活性。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，傅里叶红外光谱，核磁共振，紫外-可见光谱和表面酸度测量。结果表明，燃烧合成催化剂活性增强的主要因素是表面羟基的增加和带隙的减小。较低的带隙可归因于碳包合到TiO2中，形成TiO2- 2xcx V-O2。
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 TiO2-2xCx V-O2.