1 research outputs found
Influence of gold particle size on the photocatalytic activity for acetone oxidation of Au/TiO(2) catalysts prepared by dc-magnetron sputtering
Two series of Au/TiO2 materials with different gold content have been prepared by dc-magnetron sputtering
on ceramic shaped pure anatase or Degussa P25 TiO2. The time of deposition was varied between 1
and 20 min in order to obtain different thickness and nanoparticle size of the gold films. For comparison
samples with Au loadings in the range 0.3–0.9 wt% were prepared using the deposition–precipitation
methodology. The obtained materials were characterized by X-ray diffraction (XRD), X-ray photoelectron
spectroscopy (XPS), DR-UV-Vis and atomic force and scanning electron microscopy techniques. The
photocatalytic activity was checked in the photo-oxidation of acetone under both UV and visible irradiation
conditions. Several factors were found to influence the photoactivity. An optimal Au content
corresponding to a maximum activity is observed and attributed to the occurrence of adequate titania
surface coverage and Au particle size. The support plays an important role and it was found that
pristine anatase on which gold (average particle size 7.7 nm) was deposed by dc-reactive sputtering
exhibits the maximum of the activity. Samples prepared by dc-sputtering were more active than samples
prepared by deposition–precipitation method. Also, the photocatalysts prepared using dc-reactive
sputtering showed activity under both UV and visible light irradiation, while those prepared using the
deposition–precipitation technique are active only under UV light. The most likely mechanism of gold
activation of titania is that upon light absorption, gold nanoparticles inject electrons into the titania
conduction band.The authors kindly acknowledge NATO's Scientific Affairs Division in the framework of the Science for Peace Programme Sfp 981476 for the financial support. Bogdan Cojocaru wish to thank CNCSIS PNII PD 13/2010 for financial support.Cojocarua, B.; Neatu, S.; Sacaliuc-Pârvulescu, E.; LĂ©vy, F.; Pârvulescua, VI.; GarcĂa GĂłmez, H. (2011). Influence of gold particle size on the photocatalytic activity for acetone oxidation of Au/TiO(2) catalysts prepared by dc-magnetron sputtering. Applied Catalysis B: Environmental. 107(1):140-149. doi:10.1016/j.apcatb.2011.07.007S140149107