Enhancement of TiO2 photocatalytic activity by Gd3+ doping

Gd3+ doped TiO2 nanopowders were successfully synthesised by sol-gel method using gadolinium nitrate and tetra-n-butyl titanate as the precursors. The as prepared nanopowders were characterised by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results indicated that Gd3+ doping effectively inhibits the phase transformation from anatase to rutile until 700 degrees C, which was propitious to promote the catalytic activity of the catalysts. The fine and uniform Gd3+ doped TiO2 nanopowders with the size of 10-15 nm were obtained using the 0.75 g L-1 hydroxypropyl cellulose (HPC) as dispersant for the excellent steric stabilisation. Compared with the nanocrystalline TiO2, the Gd3+ doped TiO2 nanopowders exhibited higher photocatalytic activity to methylene blue degradation.