Understanding the effects of ion-exchange in titanosilicate ETS-10: A joint theoretical and experimental study

Density functional theory (DFT) calculations within the gradient-corrected approximation (GGA) were carried out on two models of Engelhard titanosilicate (ETS-10) with the aim to elucidate the effect of ion exchange on the structural and electronic properties of the TiOTi quantum wire. The partial and full exchange of Na+ cations with alkaline, earth-alkaline, and transition metal ions have been investigated. The theoretical results have been complemented by experimental X-ray diffraction (XRD) and Raman data in the region of the TiOTi stretching of the wire. Overall, the experimental data support the theoretical findings where substitution of Na+ with K+, Ag+, and Ca2+ cause only minor structural changes in the wire while the inclusion of Zn2+, Ru3+, and Au3+ cause its partial or entire disruption.