▎ 摘 要
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 degrees C, and the second by including graphene oxide flakes in the calcined (at 500 degrees 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 degrees 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. (C) 2015 Institute of Chemistry, Slovak Academy of Sciences