Raman spectroscopic studies of silicotitanates

Silicotitanates are nanoporous materials that have been used as selective ion exchangers for removing cesium from waste streams and catalysts for promoting oxidation and hydroxylation reactions. The local bonding configurations and network charge distribution are known to influence the selectivity and reactivity of these compounds. We have synthesized a group of new silicotitanates using sol-gel and solid-state techniques. Raman spectroscopy has been used to systematically examine the vibrational behavior of these compounds. By correlating the variations of Raman spectra with titanium coordinations of these compounds, the relationship between Raman shifts and the local bonding configurations around silicon and titanium is proposed.