Effect of Ag containing (nano)particles on reactive adsorption of mustard gas surrogate on iron oxyhydroxide/graphite oxide composites under visible light irradiation

Abstract

Iron oxyhydroxide and graphite oxide (GO) composites with either 1 or 10% of GO were modified with Ag (1 or 5% of AgNP solution) using a single step in situ procedure. The synthesized samples were tested as reactive adsorbents of chloroethyl ethyl sulfide vapors (CEES). The composites had large surface areas that were slightly affected by the Ag addition. Three different kinds of Ag particles were identified: AgCl, Ag2O and Ag0. The amount of silver in the precursor solution affects the amount of deposited AgCl and its particle size. Potentiometric titration and FTIR results indicated the interactions of the Ag species with bridge and terminal hydroxyl groups on the iron oxyhydroxide and with oxygen groups of the GO surface. Energy band gaps of all materials were estimated to be in the visible light range. The composites exhibit high capacities for CEES adsorption. Ethyl vinyl sulfide and 1,2-bis(ethylthio)ethane were identified as the main reaction products of the CEES reactive adsorption. The analysis of the extracts showed the presence of oxidation products and disulfides. The Ag species had a marked catalytic effect on the formation of oxidation products and thiyl radicals.