以正硅酸乙酯和硝酸铜为前驱体, 通过溶胶-凝胶法制备了铜掺杂的二氧化硅膜, 通过FT-IR、XPS、XRD等测试方法研究了铜元素在膜材料中的存在形态, 并利用N2吸附对膜材料的孔结构进行表征, 讨论了铜掺杂量以及水/正硅酸乙酯的化学计量比对膜材料孔结构的影响, 最后初步研究了铜掺杂二氧化硅膜在水热环境下的孔结构稳定性. 结果表明, 当n(H2O):n(TEOS)= 0.5:1.0时能获得微孔结构, 铜掺杂后的二氧化硅膜仍然保持良好的微孔结构,当n(Cu):n(Si)=0.8:1.0时膜材料的孔容达到0.155 cm3/g, 孔径狭窄分布在0.5nm. 铜元素除了进入二氧化硅骨架外主要以晶态Cu单质和Cu2O存在. 铜掺杂的膜材料在水热环境下短期内能保持微孔结构, 但长期的水热环境导致膜材料孔结构的崩溃.
Copper-doped silica membranes were prepared via Sol-Gel process with tetraethylorthosilicate(TEOS) and copper nitrate as precursors. The status of copper in the membranes was detected by means of FT-IR, XPS, XRD and the pore structure was determined by N2 adsorption. The effects of copper dopant and H2O/TEOS molar ratio on the pore structure were investigated and the stability of the pore structure under hydrothermal conditions was studied in detail. The results show that when the molar ratio of TEOS to H2O is 0.5, it leads to microporous structure, with a pore volume of 0.155 cm3/g and a sharp pore size distribution centered at 0.5nm for the sample with a Cu/Si molar ratio of 0.8. A faction of copper is incorporated into silica framework by replacing silicon atoms, and the residual mainly exists as crystalline phase such as Cu and Cu2O outside the framework. The microporous structure of the doped samples could be preserved for a short time (240h) under hydrothermal conditions but finally collapsed after further hydrothermal treatment.
参考文献
| [1] | |
| [2] | |
| [3] | |
| [4] | |
| [5] | |
| [6] | |
| [7] | |
| [8] | |
| [9] | |
| [10] | |
| [11] | |
| [12] | |
| [13] | |
| [14] | |
| [15] | |
| [16] | |
| [17] | |
| [18] | |
| [19] | |
| [20] | Turov V V, Mironyuk I F. Adsorption layers of water on the surface of hydrophilic, hydrophobic and mixed silicas. Colloids and Surfaces A:?Physicochemical and Engineering Aspects, 1998, 134(3): 257&ndash |
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