Silver-Loaded Aluminosilicate Aerogels As Iodine Sorbents

In this paper, aluminosilicate aerogels were used as scaffolds for silver nanoparticles to capture I2(g). The starting materials for these scaffolds included Na–Al–Si−O and Al–Si–O aerogels, both synthesized from metal alkoxides. The Ag0 particles were added by soaking the aerogels in aqueous AgNO3 solutions followed by drying and Ag+ reduction under H2/Ar to form Ag0 crystallites within the aerogel matrix. In some cases, aerogels were thiolated with 3-(mercaptopropyl)trimethoxysilane as an alternative method for binding Ag+. During the Ag+-impregnation steps, for the Na–Al–Si−O aerogels, Na was replaced with Ag, and for the Al–Si–O aerogels, Si was replaced with Ag. The Ag-loading of thiolated versus nonthiolated Na–Al–Si–O aerogels was comparable at ∼35 atomic %, whereas the Ag-loading in unthiolated Al–Si–O aerogels was significantly lower at ∼7 atomic % after identical treatment. Iodine loadings in both thiolated and unthiolated Ag0-functionalized Na–Al–Si–O aerogels were >0.5 mI ms–1 (denoting the ma...