Tuning of selective solar photocatalysis by Mn^sup 2+^ decorated nanocrystalline mesoporous TiO^sub 2

We report a novel design for visible light activated mesoporous titania (TiO2) for selective photocatalysis. The resulted TiO2 nanomaterials were characterized by Transmission Electron Microscopy (TEM), Powder X-ray Diffraction (PXRD), Fourier Transformed Infra-Red (FTIR) spectroscopy, BET surface area measurement and Ultra violet-visible (UV-Vis) spectroscopy. The selective photocatalysis was tested by measuring the rate of degradation of aqueous dye mixture of methyl orange (MO) and methylene blue (MB), and the rate of selective degradation of the dye mixture was tuned by varying the surface charge on the TiO2. The surface charge was probed with zeta (ζ) potential measurements. The ζ-potential measurement showed that the selectivity of dye degradation depended on the surface charge present on the TiO2 nanomaterial.