科研之友
微信
新浪微博
Facebook
分享链接
摘要
Desorption experiments performed on four CLI-adsorbed palygorskites Suggest that the leached CIA 21 ion originates at the Surface and/or net-like interstice of the palygorskite fibres. The leached fraction, calculated from the quantities of adsorbed Cu 2 before and after desorption, is <I%. This may indicate that the majority of Cu is in inaccessible structural sites. X-ray difftaction, X-ray photoelectron spectroscopy, Fourier transform infrared (FTIR) spectroscopy and electron spin resonance (ESR) were used to determine the ii-iiiieralogical character or the CLI-adsorbcd palygorskite. Two photoclectron lines at 932.5 and/or 933.7 eV in the narrow scan CU 2P3/2 spectra show that CIA adsorbed on the surface of paiygorskite is in the C11' and CU21 state. The stretching vibrations of the octahedral cation shift -3-5 cm-1 towards a greater wavenumber in the FTIR spectra Of CLI-adsorbed palygorskite. It can be deduced that the Cu 2 is trapped in the channel of the paly-orskite structure. The ESR spectra of the palygorskite give g values of 2.34, 2.12, 2.08 and 2.05, Suggesting that Some CIA ions cannot be reached by W. These results confirm that CU is adsorbed by palygorskite via three possible mechanisms: (I) the Cu is adsorbed onto the Surface or in a net-like interstice, and its oxidation states are +1 and +2; (2) Cu forms a complex ion [CLI(H20)4]21 or [Cu(H 'o)(,121, and is trapped in the channel; or (3) Cu enters into the hexagonal channel of the tetrahedral sites or the unoccupied octahedral sites of palygorskite.
- 出版日期2008-6
- 单位南京大学
