Photocatalytic degradation of methylene blue dye over novel spherical mesoporous Cr2O3/TiO2 nanoparticles prepared by sol-gel using octadecylamine template

This research work demonstrate a facile, low cost and effective route for synthesis spherical mesoporous Cr2O3/TiO2 nanoparticles by sol-gel method and tailoring the particle structure using octadecylamine as structure and pore directing agent. X-ray diffraction [XRD], Fourier transformer infra-red [FTIR], N-2-adsorption-desorption isotherm, Energy dispersive X-ray [EDX], High resolution transmission electron microscope [HRTEM] and Selected area electron diffraction [SAED] were selected to investigate the physicochemical features of the prepared nanoparticles. However, the photocatalytic reactivity was tested by following the photocatalytic degradation of methylene blue dye. Octadecylamine is an effective template with its reactive amino group is selected to manipulate nanoparticle structure with various mesoporous cavities that allow the diffusion the dye molecules. However, incorporation of chromium oxide is remarkably reduce the particle dimension, increase the surface area, create new mesoporous channels, the band gap energy of titania and limiting the electron-hole recombination. The positive synergetic effects of titania nanoparticles and chromium oxide including the electron transfer from titania conduction band to Cr2O3 energy levels was considered a primary cause for reduction in band gap energy and limiting the recombination of the charge carriers which enhance the oxidizing power for dye photodegradation. TOC and COD results indicate the removal of 90% of methylene blue dye into CO2 and H2O. The regeneration of the photocatalyst for 6-successsive repeated cycle indicating removal of 78% of wt after the six cycles revealing the high stability of the photocatalyst against corrosion upon expose to UV irradiations.