[5]. Y Nosaka et al. (2005) prepared
nitrogen-doped TiO2 by using organic compounds in deference N source such as urea, Guanidine
Hydrochloride and Guanidine Carbonate. The N source of guanidine carbonate was shown the best
photocatalytic activity respond under visible light at wavelength longer than 420 nm. Y. Cong et al.
(2006) can be prepared nitrogen-doped TiO2 by a wet method, i.e., a microemulsion-hydrothermal
method. However, the mechanochemical method by using a high-speed ball milling of P25 TiO2 with
nitrogen source such as ammonia solution, hexamine and urea that reported by R. Rattanakam et al.
(2009), can absorbed light of wavelength up to 545 nm. Although the particle from mechanochemical
method were agglomerated. Nitrogen-doped TiO2 has been prepared by sputtering, ion implantation,
chemical vapor deposition, sol-gel, oxidation of TiN, derect nitridation of TiO2