MECHANOCHEMICAL SYNTHESIS OF ION-EXCHANGE SILVER FORMS OF POLYANTIMONIC ACID

Abstract

The possibility of synthesising ion-substituted forms of hydrated silver antimonates has been studied. For the synthesis, the method of mechanochemical activation of the components of an inorganic mixture consisting of polyantimonic acid (PAA) with composition and silver nitrate with the concentration range from 0.0 to 1.0 has been applied. The results of studies of the phase composition of the synthesized compounds and their structural features are presented. Using the Rietveld method, the parameters of the crystal lattice of PAA hydrated ionsubstituted silver forms with a pyrochlore-type structure have been refined. The model for the occupation of metal ions by crystallographic positions has been proposed: the framework of the structure of the compounds is formed by 16c- and 48f-positions, in which Sb5+ and O2- are statistically located; hydrated oxonium ions (H3O+) and silver ions occupy 16d- and 8b-positions respectively. It has been shown that the synthesis of silver forms of PAA is preferably carried out by the mechanochemical synthesis, which results in the complete substitution of proton groups by silver ions in the structure of the compounds.