Two nano-titania catalysts were prepared using two economically varying titanium precursors: titanium tetrachloride (A) and titanium isopropoxide (B). The catalysts were calcined at temperatures of 500°C, 600°C and 700°C and characterized using X-ray diffraction (XRD), electron diffraction (ED), BET surface properties and high resolution transmission microscopy (HRTEM). The calcined catalysts were found to differ markedly in their physical characters and TiO 2 phases produced as well as their photocatalytic activities. The anatase titania phase diminished from 100% to 83% in TiO 2 A but from 64% to zero in TiO 2 B via temperature increase from 500°C to 700°C, due to transforming anatase to rutile. The brookite TiO 2 phase only appeared (17%) in catalyst B500. In general, the catalyst of choice is A600 by virtue of many compositional, economical and catalytic advantages.