The X-Ray Photoelectron Spectroscopy of Copper Complexes in the Interlayer Space of Clay Minerals.

Abstract

X-ray photoelectron spectroscopy (XPS) was used to characterize the copper ion of 1, 10-phenanthroline (phen) complexes in the interlayer space of natural montmorillonite and artificial saponite. [Cu(phen)2]2+ and [Cu(phen)3]2+ were intercalated into the minerals instead of ion-exchangeable cations occupying the original interlayer space. Loading amount of complex can be varied up to 170% of cation exchange capacity (CEC) of each clay minerals. Cu(II) 2p photopeakes of [Cu(phen)2]2+ and [Cu(phen)3]2+ in saponite remarkably decrease as loading amount decreases from 170 to 50%, while Cu(I) photopeaks increase by photoreduction. X-ray diffraction (XRD) indicated that there was sufficient space to exist [Cu(phen)2]2+ without any distortion at 170%. In montmorillonite, there is sufficient space even at 50% of CEC for [Cu(phen)3]2+ and [Cu(phen)2]2+. XPS spectra suggest two or more binding state of the complexes at Interlayer space of montmorillonite.