Wrinkled-SiO2@TiO2core@shell particles for removal of pollutants in water

KEYLA M. FUENTES; MARÍA L. MARTÍNEZ RICCI; MARÍA CLAUDIA MARCHI; SARA A. BILMES; ROBERTO CANDAL

Namur

Conferencia; Fourth International Conference on Advanced Complex Inorganic Nanomaterials; 2018

Universidad de Namur

Wrinkled-SiO2@TiO2core@shellparticles for removal of pollutants in waterKeyla M. Fuentes1,2,María L. Martínez Ricci1, María Claudia Marchi1,3,Roberto Candal4,Sara A. Bilmes*11Institutode Química Física de los Materiales, Medio Ambiente y Energía- INQUIMAE,DQIAQF, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires,Ciudad Universitaria, Pabellón 2, C1428EHA, Buenos Aires, Argentina.(*email:sarabil@qi.fcen.uba.ar)2Departamentode Química Aplicada, Facultad de Ingeniería, Universidad Central de Venezuela,Caracas, Venezuela3Centrode Microscopías Avanzadas - Instituto de Física de Buenos Aires (IFIBA-CONICET),FCEyN-UBA, Ciudad Universitaria, Pabellón 1, C1428EHA, Buenos Aires, Argentina.4Instituto de Investigación e Ingeniería Ambiental, CONICET,Universidad Nacional de San Martín, Provincia de Buenos Aires, Argentina  Silica meso-structuredparticles decorated with TiO2 nanoparticles (NPs) are proposed as anefficient system for removing and degrading model compounds in aqueoussolutions. The basic idea is to providea material able to efficiently retainhydrophilic or hydrophobic pollutants that may be further degraded byphotocatalysis. Retention capacity can be accomplished by derivatized poroussilica, whereas efficient photocatalysis requires < 10 nm anatase particlesdispersed on the silica surface in order to have an efficient light harvesting[i].Here we present theefficiency of this system for removal of Crystal Violet (CV) or phenol. Thegeneral strategy is the preparation of porous wrinkled silica particles in apseudoternary system composed by urea in water, CTAB - 1-butanol, andcyclohexane. These monodisperse silica particles (Fig.1-a) with diameter tunedin the 300-600 nmare further decorated with TiO2 NPs fromTi-isopropoxide by hydrothermal pathway. The amount of TiO2effectivelydeposited depends on the structure of the pore?s walls.On naked corrugated Silicaparticles TiO2 NPs 7 nm diameter are distributed on the pore?ssurface (Fig. 1-c), whereas when pores are filled with surfactant the samehydrothermal treatment leads to higher loading andagglomerated structures onthe surface (Fig 1 ?b). The optimal photocatalytic activity is obtainedfor TiO2 deposits where NPs can be considered as quasi-isolated. Onthe other hand, removal of pollutants from solution is improved when thestructure of silica is derivatized with surfactant molecules which favor theirsorption.[i]S.Ullah; E.P. Ferreira-Neto; A. A. Pasa; C. C.J. Alcântara; J. J.S. Acuña; S. A.Bilmes; M. L. Martínez Ricci; R. Landers; T. ZampieriFermino; U. P.Rodrigues-Filho ;ApplCatalysis B179, 333, (2015)