abstract
Composite microporous SiO2-TiO2 spheres and micro/mesoporous TiO2 spheres were prepared via the template free two-step synthetic route using aqueous peroxotitanate solution and tetraethyl orthosilicate (TEOS) as precursors. Both the composite SiO2-TiO2 and pure TiO2 spheres prepared by the solvent-exchange method were initially non-porous, but the applied reflux treatment in water-ethanol suspension successfully transformed them into microporous materials with high apparent surface areas approaching 500 m(2).g(-1) and the micropore volume of 0.17 cm(3).g(-1), while maintaining the same morphology. The prepared composites retained high values of pore volume and specific surface area up to 400 degrees C of thermal treatment temperature. The crystallization of TiO2 into the anatase phase in the mixed oxide occurred only at 700 degrees C, that process was also accompanied by the significant reduction of pore volume, as well as apparent surface area values. The prepared materials were tested as adsorbents for the lead(II) removal; they demonstrated high adsorption capacities, reaching 340 mg(Pb2+).g(-1) Moreover, the mixed silica-titania oxide was found to be more efficient adsorbent at low pH values.
keywords
SOL-GEL PROCESS; MIXED OXIDES; TIO2 SPHERES; SILICA; ADSORPTION; TIO2-SIO2; CATALYSTS; MEMBRANE; DESIGN; WATER
subject category
Materials Science
authors
Morozov, R; Krivtsov, I; Avdin, V; Amghouz, Z; Gorshkov, A; Pushkova, E; Bol'shakov, O; Bulanova, A; Ilkaeva, M
our authors
Marina Ilkaeva
Junior Researcheracknowledgements
South Ural State University is grateful for financial support of the Ministry of Education and Science of the Russian Federation (grant No 16.2674.2014/K). University of Oviedo gratefully acknowledges financial support from the Spanish MINECO (MAT2013-40950-R and MAT2016-78155-C2-1-R). Igor Krivtsov thanks for the support the Russian Foundation for Basic Research 16-29-10757-ofi.