Abstract
Natural silica source from Red Sea Desert mine - Egypt for white sand has been successfully employed as a starting precursor for hydrothermal preparation of titanosilicate types natisite and sitinakite. Interestingly the structure of the starting precursor of the silica source plays a role in controlling the type of the titanosilicate produced. ETS-4, natisite, sitinakite plus the doped ETS-4 and natisite with vanadium have been studied for hydrogen uptake. The samples adsorbed 2-2.3 wt% hydrogen at -193 degrees C and 20 bar applied hydrogen pressure. The dense natisite structure prepared in this study is found to be superior to those prepared using commercially available silica. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.