Photocatalytic activity of TiO 2 nanoparticles: effect of thermal annealing under various gaseous atmospheres

The structure, composition and photocatalytic activity of TiO 2 nanoparticles annealed in various gas atmospheres (N 2 , NH 3 and H 2 ) were studied in this work. The effect of treatment on crystal structure, particle size, chemical composition and optical absorbance were assessed by means of x-ray diffraction, transmission electron microscopy, x-ray photoelectron spectroscopy and diffuse optical reflectance/transmittance measurements, respectively. Photocatalytic properties of the materials were evaluated by three different methods: degradation of methyl orange in water, killing of Staphylococcus aureus bacteria and photogeneration of radicals in the presence of 3-carboxy-2,2,5,5-tetramethyl pyrrolidine-1-oxyl (PCA) marker molecules. The results indicate that the correlation between pretreatment and the photocatalytic performance depends on the photocatalytic processes and cannot be generalized.

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2012-11-01 18:02:25

Source: http://nanochemistry.blogspot.com/2012/11/photocatalytic-activity-of-tio-2.html