Surface Modification of TiO2 Nanoparticles with Vitamin B12: Relationships between Vitamin B12 Content and Its Optical Properties

Anatase TiO2 nanoparticles (NPs) with particle size of 10-20 nm were prepared via sol gel technique. The as-synthesized NPs were immerged in vitamin B-12 (VB12) solutions with different concentrations. The influences of the solution concentration on photoluminescence and photocatalytic activity of the modified NPs were studied. Fourier transform infrared spectroscopy (FTIR) results demonstrated that TiO2 NPs adsorb VB12 molecules and that a new band is formed at similar to 2300 cm(-1). The VB12 loading process led to diminishing of the aggregation of NPs and formation of a fibre shape structure. The best photoactivity and PL effect among the modified samples was related to sample 'd'. The optimum processing conditions to achieve this sample was found to be VB12 concentration of 5 g/L.