Low temperature synthesis and photocatalytic properties of mesoporous TiO2 nanospheres

Facile one-step synthetic method for the fabrication of uniform mesoporous TiO2 nanospheres was reported on the basis of template-directed deposition and in situ template-sacrificial dissolution, in which SiO2 nanospheres was employed as the template and (NH4)2TiF6 was used as the precursor. The deposition of TiO2 nanoparticles on the surface of template is accompanied with the dissolution of SiO2 spherical cores by HF generated during the hydrolysis of (NH4)2TiF6 in the reaction. The obtained products were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), N2 adsorption-desorption analysis, and UV-visible diffuse reflectance spectroscopy. Furthermore, the photocatalytic activity of samples was evaluated by photocatalytic decolorization of three typical dyes (methyl orange, methylene blue, and rhodamine B) at ambient temperature under UV illumination. The results indicate mesoporous TiO2 nanospheres exhibited good photocatalytic activity for the degradation of different dyes. These monodisperse mesoporous TiO2 nanospheres should find various potential applications in photocatalysis, catalysis, solar cell, separation and purification processes.