Effects of Ni doping on photocatalytic activity of TiO(2) thin films prepared by liquid phase deposition technique

摘要

The TiO(2) thin films doped by Ni uniformly and non-uniformly were prepared on glass substrate from an aqueous solution of ammonium hexa-fluoro titanate and NiF(2) by liquid phase deposition technique. The addition of boric acid as an F(-) scavenger will shift the equilibrium to one side and thereby deposition of the film is progressed. The rate of the reaction and the nature of deposition depend on growing time and temperature. The resultant films were characterized by XRD, EDAX, UV and SEM. The result shows that the deposited films have amorphous background, which becomes crystalline at 500 degrees C. The EDAX data confirms the existence of Ni atoms in TiO(2) matrix. XRD analysis reveals the peaks corresponding to Ni but no peak of crystalline NiO was found. The transmittance spectra of Ni uniformly and non-uniformly doped TiO(2) thin films show 'blue shift and red shift', respectively. Ni-doped TiO(2) thin films can be used as photocatalyst for the photodegradation of methyl orange dye. It was found that, organic dye undergoes degradation efficiently in presence of non-uniformly Ni-doped TiO(2) thin films when compared to uniformly doped films and pure TiO(2) films under visible light. The photocatalytic activity increases with increase in the concentration of Ni in case of nonuniformly doped thin films but decreases with the concentration when uniformly doped thin films were used.