A new approach to optimize the synthesis parameters of TiO2 microsphere and development of photocatalytic performance

In this study, Titanium (IV) Oxide (TiO2) microspheres were synthesized by hydrothermal method, and Cerium Oxide (CeO2) nanoparticles in the ratios of 0.1, 0.25, 0.5 and 1 mol% were loaded onto these microparticles by surfactant-assisted (Pluronic 123) sol-gel method. The crystal properties and surface morphology of the synthesized TiO2-CeO2 hybrid photocatalysts were investigated by X-ray diffraction method (XRD) and field emission scanning electron microscope (FESEM). Bond structures and surface areas were examined by Fourier-transform infrared spectroscopy (FTIR), Raman and Brunauer-Emmett-Teller (BET) analysis, respectively. XRD patterns with (101) and (200) main planes show that nanoparticles have anatase TiO2 phase. Also, A(1g), B-1g and E-g Raman modes confirms anatase TiO2 phase. In addition, with CeO2 doping, while the average crystallite size of nanoparticles decreased, their surface area increased. The photocatalytic activity of the prepared photocatalysts were investigated by degradation of the methylene blue (MB) under UV light (lambda = 365 nm). The results showed that the surface area and crystal structure of hybrid structure and interface interaction between TiO2 and CeO2 have a significant effect on photocatalytic performance. The 0.1% CeO2-TiO2 photocatalyst degraded almost 95% of the MB solution in about 60 min, while for TiO2 microspheres this value is around 80%. Also, we observed that 0.1% CeO2-TiO2 led to about 1.4 times higher reaction rate in comparison to TiO2. Results showed that the hybrid photocatalysts has a higher performance than bare TiO2 microspheres.