Synthesis of Functional Materials from Basic Bismuth(III) Nitrates

Main synthetic routes to bismuth-containing functional materials from basic bismuth nitrates with the compositions [Bi₆O₄(OH)₄](NO₃)₆·H₂O and [Bi₆O₅(OH)₃](NO₃)₅·3H₂О, which are high-purity products of hydrolytic processing of technological solutions with respect to the content of metal impurities relative to bismuth, are considered. Basic bismuth oxalate and bismuth(III) oxide salicylate with the compositions BiOH(C₂O₄) and BiO(C₇H₅O₃), respectively, were obtained by treatment of basic bismuth nitrates with solutions of the corresponding carboxylic acids. The compositions of the compounds were identified by X-ray phase and chemical analyses, IR and Raman spectroscopy, and thermogravimetry. The conditions for oxidative thermolysis of BiO(C₇H₅O₃) to obtain the tetragonal modification of bismuth oxide β-Bi₂O₃ have been determined. The processes of thermolysis of the synthesized bismuth carboxylates in an inert atmosphere and in vacuum to obtain Bi–C composites have been considered.