二氧化硅吸附铝离子的X射线光电子能谱(XPS)表征

Study on the Adsorption of Aluminum Ions on Silica by X-Ray Photoelectron Spectroscopy

用X射线光电子能谱技术研究了不同pH条件下二氧化硅对铝离子的吸附作用。在pH分别为3.74、4.25和4.88条件下,吸附在二氧化硅表面的铝离子的Al2p电子结合能依次为74.30、74.90、75.10eV。根据Al3+在水溶液中的一级水解常数pK1=4.99,认为在pH=3.74条件下,吸附在二氧化硅表面的铝离子的形态为Al3+,而在其余两种pH条件下表面铝离子的形态为Al(OH)2+。

X-ray photoelectron spectroscopy was used to examine the chemical nature of aluminum (Al) ions adsorbed on silica surface at pH 3. 74,4. 25,and 4. 88. The atomic percentage of adsorbed Al ions on silica surface increases with pH. The binding energy for aluminum ions on silica indicates that Al is probably as the form of Al3+ at pH 3. 74 with binding energy of 74. 30eV, and hydroxyl forms of Al(OH)2+ or Al(OH)2+ at pH 4. 25 and 4. 88 with higher binding energy.