Synthesis and characterisation of Gd-doped mesoporous TiO2 materials

Using multi-walled carbon nano-tubes (MWNTs) as the template, Gd³⁺-doped mesoporous TiO₂ (M-TiO₂) material was prepared by the homogeneous precipitation-assisted template method. The as-prepared photo-catalysts were characterised using X-ray diffraction, scanning electron microscopy, nitrogen adsorption/desorption and ultraviolet-visible (UV-vis) diffuse-reflection spectroscopy analyses. The photo-catalytic properties of Gd³⁺-doped M-TiO₂ were primarily investigated by the photo-degradation of methyl orange under Xe-lamp irradiation and compared with those of pure M-TiO₂ and the commercial photo-catalyst Degussa P25. The results showed that the as-synthesised samples were of anatase crystalline phase and had red shifts in their UV-vis patterns with different Gd³⁺-doping concentrations. Gd³⁺-adding at 0.12 mol% could significantly enhance the photo-catalytic properties of the M-TiO₂ material and the rate of photo-degradation of methyl orange reached 97.3% under Xe-lamp irradiation for 150 min.