We report a template-free process to fabricate (I2)n-C-codoped meso/nanoporous TiO2 nanocrystallites. I2 nanoparticles in I2-hydrosol were used as seeds to initial the nucleation of a precursory TiO2 shell formed by the hydrolysis of organotitanium molecules. The hybridized jumbles were further calcinated at different temperatures. The resulting (I2)n-C-codoped meso/nanoporous TiO2 structure was confirmed by transmission electron microscopy (TEM), X-ray diffraction (XRD), Brunauer−Emmett−Teller (BET) isotherm adsorption of N2. UV−visible diffuse reflectance spectroscopy (DRS) showed that (I2)n-C-codoped porous TiO2 samples have a strong absorption between 400−700 nm. The formation mechanism of (I2)n-C-codoped meso/nanoporous TiO2 spheres is discussed. Under visible light radiation, our samples exhibit superior ability in the photocatalytic degradation of methylene blue to that of the only C-doped TiO2 or to the commercial P25 TiO2 nanoparticles. The origin of the enhanced visible light−light driven photoc...