The syntheses, characterizations, and photocatalytic activities of silver, platinum, and gold doped TiO2 nanoparticles

Abstract

Different weight percentages of Ag, Pt, and Au doped nano TiO2 were synthesized using the acetic acid hydrolyzed sol-gel method. The crystallite phase, surface morphology combined with elemental composition and light absorption properties of the doped nano TiO2 were comprehensively examined using X-ray diffraction (XRD), N2 sorption analysis, transmission electron microscopic (TEM), energy dispersive X-ray, and DRS UV-vis analysis. The doping of noble metals stabilized the anatase phase, without conversion to rutile phase. The formation of gold nano particles in Au doped nano TiO2 was confrmed from the XRD patterns for gold. The specifc surface area was found to be in the range 50 to 85 m2/g. TEM images confrmed the formation a hexagonal plate like morphology of nano TiO2. The photocatalytic activity of doped nano TiO2 was evaluated using 4-chlorophenol as the model pollutant. Au doped (0.5 wt %) nano TiO2 was found to exhibit higher photocatalytic activity than the other noble metal doped nano TiO2, pure nano TiO2 and commercial TiO2 (Degussa P-25). This enhanced photocatalytic activity was due to the cathodic infuence of gold in suppressing the electron-hole recombination during the reaction. © Copyright The Korean Society of Environmental Engineers.