<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Malwadkar, Sachin S.</style></author><author><style face="normal" font="default" size="100%">Gholap, Ramkrishna S.</style></author><author><style face="normal" font="default" size="100%">Awate, Shobhana V.</style></author><author><style face="normal" font="default" size="100%">Korake, Prakash V.</style></author><author><style face="normal" font="default" size="100%">Chaskar, Manohar G.</style></author><author><style face="normal" font="default" size="100%">Gupta, Narendra M.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Physico-chemical, photo-catalytic and O-2-adsorption properties of TiO2 nanotubes coated with gold nanoparticles</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Photochemistry and Photobiology A-Chemistry</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Acetaldehyde oxidation</style></keyword><keyword><style  face="normal" font="default" size="100%">Gold co-catalyst</style></keyword><keyword><style  face="normal" font="default" size="100%">O-2-adsorption</style></keyword><keyword><style  face="normal" font="default" size="100%">Photo-catalytic activity</style></keyword><keyword><style  face="normal" font="default" size="100%">TiO2 nanotubes</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year><pub-dates><date><style  face="normal" font="default" size="100%">MAR</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">1</style></number><publisher><style face="normal" font="default" size="100%">ELSEVIER SCIENCE SA</style></publisher><pub-location><style face="normal" font="default" size="100%">PO BOX 564, 1001 LAUSANNE, SWITZERLAND</style></pub-location><volume><style face="normal" font="default" size="100%">203</style></volume><pages><style face="normal" font="default" size="100%">24-31</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Gold-containing titania nanotubes (Au/NT) were found to display higher activity for photooxidation of acetaldehyde, as compared to corresponding gold-free nanotubes and also a Degussa P-25 catalyst. Besides CO2 as a major reaction product, small amounts of H-2, CH4, CO, H2O and CH3COOH were also formed, irrespective of the catalyst employed. High-resolution TEM examination showed that most of the gold particles in Au/NT were of 1.5-5 nm size, distributed both within and at outside surface of the nanotubes. Some larger size (10-70 run) clusters were also seen at the external surfaces, particularly in the samples calcined at an elevated temperature. The temperature-programmed desorption measurements revealed that, compared to P-25 TiO2, a significant entrapment of O-2 occurred at two distinct tubular sites of NT samples, corresponding activation energy of desorption (E,) being around 36 and 41 kcal mol(-1). On the other hand, gold nanoparticles in Au/NT served as independent low-energy (E-a = 26 kcal mol(-1)) sites for adsorption/activation of O-2. These adsorptive properties of TiO2 and Au were lost completely on calcination, thus revealing a crucial role played by the particle size. In situ IR spectroscopy results showed that room-temperature exposure to acetaldehyde + air gave rise to a molecularly bound state, i.e. CH3CHOad, over both NT and Au/NTsamples, which in turn transformed quickly to yield certain acetate (CH3COOad-) and formate (HCOOad-) type transient species with the involvement of the surface OH groups. The decomposition and oxidation of these surface species with the help of O-2(-), O-ad and hydroxyl ion radicals (OH-) formed at photo-excited Au/NT interfaces led to the reaction products mentioned above. We conclude that, besides electron-hole charge separation, the adsorptive properties of host matrix and nanosize gold may together play a significant role in deciding the photo-catalytic properties of Au/TiO2. (C) 2008 Elsevier B.V. All rights reserved.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">1</style></issue><custom3><style face="normal" font="default" size="100%">Foreign</style></custom3><custom4><style face="normal" font="default" size="100%">2.243</style></custom4></record></records></xml>