ISSN print edition: 0366-6352
ISSN electronic edition: 1336-9075
Registr. No.: MK SR 9/7
Morphology, structure, and photoactivity of two types of graphene oxide–TiO2 composites
Anca Peter, Leonard Mihaly-Cozmuta, Anca Mihaly-Cozmuta, Camelia Nicula, Agnieszka Jastrzębska, Patrycja Kurtycz, and Andrzej Olszyna
Department of Chemistry, Technical University Cluj Napoca, Victor Babes 76, 430083, Baia Mare, Romania
Abstract: Two types of graphene oxide-TiO2 composites were prepared: one by including graphene oxide flakes in the TiO2 sol, followed by thermal treatment (GI composite) at 300°C, and the second by including graphene oxide flakes in the calcined (at 500°C) TiO2 xerogel (GII composite). The composites were characterized by SEM, TEM-EDS, TEM-SADP, STEM-HAADF, HRTEM coupled with FT, XRD, and XPS. Photocatalysis results were fitted to different kinetic models (pseudo-first and pseudo-second kinetics, intraparticle Weber-Morris diffusion, film diffusion, and external mass transfer). The results showed that by introducing graphene oxide flakes in the TiO2 sol, followed by thermal treatment at 300°C (GI composite), an efficient graphene oxide-TiO2 catalyst with high specific surface area, heterogeneity, and many graphitized areas can be obtained. Complete crystallization of the composite is not the key issue for the best photoactivity achievement. The rate limiting step in the photocatalytic process is the photooxidation of SA molecules on the TiO2 surface.
Keywords: graphene oxide-TiO2 – photocatalytic activity – kinetic model – morpho-structural characterization
Full paper is available at www.springerlink.com.
Chemical Papers 69 (6) 839–855 (2015)