Synthesis and intracrystalline oxidation of nitrite-intercalated layered double hydroxides

Nitrite-intercalated LDHs could be prepared by a two-stage process that involves coprecipitation in the presence of nitrite ions followed by stirring the product with excess of nitrite ions. The nitrite ion lies flat in these LDHs with its C-2-axis lying approximately perpendicular to the crystallographic c-axis. The interlayer nitrite ions in these LDHs could be quantitatively oxidized to nitrate ions using H2O2 solution the LDHs thus obtained the nitrate ion lies flat with its c(3)-axis parallel to the crystallographic c-axis (D-3h symmetry) in the interlayer region resulting in lower basal spacing. (C) 2008 Elsevier Inc. All rights reserved.