Adsorption of Platinum(IV) by a Composite Based on Silicon Dioxide and Copolymer of 4-Vinylpyridine and 2-Hydroxyethylmethacrylate

Abstract—The adsorption of platinum(IV) solutions by a composite based on silicon dioxide and copolymer of 4-vinylpyridine and 2-hydroxyethylmetacrylate in hydrochloric acid solutions has been studied. The maximum efficiency of extraction of platinum(IV) ions has been detected in a solution of HCl with a concentration of 1 mol L^–1 at a temperature of 338 K (sorption capacity equal to 188 mg g^–1). The interaction of platinum (IV) with the surface of the composite is a result of chemisorption. The models of Langmuir, Freundlich, and Dubinin–Radushkevich have been used to describe the nature of adsorption. Adsorption kinetics was assessed using the models of Boyd–Adamson, pseudofirst and pseudosecond orders, and Elovich.