03004nas a2200265   4500008004100000022001400041245011700055210006900172260006900241300001000310490000800320520201400328653002702342653002102369653001902390653002902409653001902438100002602457700002702483700002402510700002402534700002502558700002402583856013102607       2009                        eng d  a1010-603000aPhysico-chemical, photo-catalytic and O-2-adsorption properties of TiO2 nanotubes coated with gold nanoparticles0 aPhysicochemical photocatalytic and O2adsorption properties of Ti  aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcMAR  a24-310 v2033 a<p>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.</p>10aAcetaldehyde oxidation10aGold co-catalyst10aO-2-adsorption10aPhoto-catalytic activity10aTiO2 nanotubes1 aMalwadkar, Sachin, S.1 aGholap, Ramkrishna, S.1 aAwate, Shobhana, V.1 aKorake, Prakash, V.1 aChaskar, Manohar, G.1 aGupta, Narendra, M.  uhttps://library.ncl.res.in/content/physico-chemical-photo-catalytic-and-o-2-adsorption-properties-tio2-nanotubes-coated-gold-001985nas a2200229   4500008004100000022001400041245007500055210006900130260009200199300001400291490000700305520116500312653002401477653001701501653001901518653002101537100002401558700002301582700002001605700002101625856010901646       2012                        eng d  a0277-224800aPhotocatalytic degradation of phosphamidon using Ag-doped ZnO nanorods0 aPhotocatalytic degradation of phosphamidon using Agdoped ZnO nan  a4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLANDbTAYLOR & FRANCIS LTDcJAN  a1075-10850 v943 a<p>The photocatalytic degradation of the organo-phosphorous pesticide phosphamidon at low concentration in aqueous solution on Ag-doped ZnO nanorods was investigated. Nanosized Ag-doped ZnO rods were synthesized by using a microwave assisted aqueous method. High molecular weight polyvinyl alcohol was used as a stabilizing agent. Composition and structure were investigated using energy-dispersive X-ray spectroscopy (EDAX) and X-ray diffraction (XRD). The XRD pattern reveals that ZnO nanorods are of hexagonal wurtzite structure. The average crystallite size calculated from Scherrer's relation was found to be 30 nm. The effects of catalyst loading, pH value, and initial concentration of phosphamidon on the photocatalytic degradation efficiency using Ag-doped ZnO nanorods as a photocatalyst have been discussed. The results revealed that Ag-doped ZnO nanorods with a diameter of 30 nm showed highest photocatalytic activity at a surface density of 1 g dm(-3). The catalyst doped with 0.2 mol% Ag is effective for the degradation of phosphamidon with visible light. This opens a new possibility to decompose pesticides that are present in wastewater.</p>10aAg-doped zinc oxide10aphosphamidon10aPhotocatalysis10aPhotodegradation1 aKorake, Prakash, V.1 aSridharkrishna, R.1 aHankare, P., P.1 aGaradkar, K., M.  uhttps://library.ncl.res.in/content/photocatalytic-degradation-phosphamidon-using-ag-doped-zno-nanorods-0