Zhang Feng-Li, Zheng Yuan-Hui, Zhan Ying-Ying, Lin Xing-Yi, Zhang Han-Hui, Zheng Qi
National Engineering Research Center of Chemical Fertilizer Catalyst, Fuzhou University, Fuzhou 350002, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2009 Aug;29(8):2166-70.
In the present paper, ordered mesoporous silica (KIT-6) as support, nanosized TiO2 into KIT-6 was synthesized by titanium tetraisopropoxide hydrolysis. Then silver was loaded by deposition-precipitation method. Ag-TiO2/KIT-6 composite nanosized photocatalyst was firstly synthesized and a series of correlated catalysts were synthesized by the same preparation method. Methyl orange is presently adopted as a representative organic pollutant to evaluate the photocatalytic performance of the as-synthesized catalysts. The order of photocatalytic activity of the as-synthesized samples was found as Ag-TiO2/KIT-6 > Ag/TiO2 > TiO2/KIT-6 > TiO2 > Ag/KIT-6. Detailed characterizations were conducted by techniques including XRD, N2 physical adsorption, XPS, UV-Vis DRS and TEM. It was found that the Ag-TiO2 /KIT-6 sample shows the highest photocatalytic activity, which should be attributed to the Ag-TiO2 heterojunction structure and higher BET surface area of the Ag-TiO2/KIT-6 sample. Ag-TiO2 heterojunction improves the separation of photogenerated electron-hole pairs, thus enhancing the photocatalytic activity; Ag-TiO2/KIT-6 sample possesses high BET surface area, which facilitates adsorption and transportation of dye molecules, also leading to higher photocatalytic activity.
在本文中，以有序介孔二氧化硅（KIT-6）为载体，通过四异丙醇钛水解法将纳米TiO₂引入KIT-6中。然后采用沉积沉淀法负载银。首次合成了Ag-TiO₂/KIT-6复合纳米光催化剂，并通过相同的制备方法合成了一系列相关催化剂。目前采用甲基橙作为代表性有机污染物来评价所合成催化剂的光催化性能。发现所合成样品的光催化活性顺序为Ag-TiO₂/KIT-6 > Ag/TiO₂ > TiO₂/KIT-6 > TiO₂ > Ag/KIT-6。通过XRD、N₂物理吸附、XPS、UV-Vis DRS和TEM等技术进行了详细表征。发现Ag-TiO₂ /KIT-6样品表现出最高的光催化活性，这应归因于Ag-TiO₂异质结结构以及Ag-TiO₂/KIT-6样品较高的BET比表面积。Ag-TiO₂异质结改善了光生电子-空穴对的分离，从而提高了光催化活性；Ag-TiO₂/KIT-6样品具有较高的BET比表面积，有利于染料分子的吸附和传输，也导致了较高的光催化活性。
