the photocatalytic activity was improved greatly compared with
P25-Degussa and HM-TiO2. For optimum condition, 0.5M of guanidine carbonate source was used, it
shown percentage degradation of MB aqueous solution at 80% with visible light irradiation for 1h. The
morphology of nitrogen-doped TiO2 is cubic nanoparticles with 50-500 nm in length.