02498nas a2200265 4500008004100000022001400041245016100055210006900216260006900285300001200354490000800366520146200374653003801836653003001874653001901904653002301923653003601946653002001982100001802002700002002020700002202040700002502062700002402087856012102111 2009 eng d a0254-058400aDoping-induced microstructural, textural and optical properties of In2Ti1-xVxO5+delta semiconductors and their role in the photocatalytic splitting of water0 aDopinginduced microstructural textural and optical properties of aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcOCT a399-4070 v1173 a

The physicochemical properties of V-doped indium titanates (In2Ti1-xVxO5-delta, 0.0 <= x <= 0.2) were investigated by using XPS, powder XRD, UV-vis, SEM and luminescence spectroscopy techniques. The Rietveld refinement of XRD data revealed that even though the V-containing samples were isostructural with In2TiO5 (orthorhombic space group Pnma), a systematic x-dependent variation was noticeable in the Ti-O bond lengths in [TiO6] octahedral units, cell parameters and in the value of delta. XPS results confirmed the coexistence of V5+ and V4+ states, leading thereby to an enhancement in oxygen non-stoichiometry in the doped samples. A loading-dependent progressive shift from 400 to 750 nm was also observed in the onset of the absorption edge, indicating a significant narrowing of the band gap. Furthermore, the samples with higher V-content were comprised of the grain clusters having larger size and an irregular shape. The UV-vis. photoluminescence and thermoluminescence studies indicate that the doping-induced lattice defects may give rise to certain closely spaced acceptor/donor energy levels in between the band gap of host matrix. The indium titanates are found to serve as stable photocatalysts for water splitting under visible light, where oxygen was the major reaction product. The role of microstructural and morphological properties in the photocatalytic activity is discussed. (C) 2009 Elsevier B.V. All rights reserved.

10aIn2Ti1-xVxO5+delta photocatalysts10aLuminescence spectroscopy10aMicrostructure10aOptical properties10aStructure-activity relationship10awater splitting1 aShah, Pallavi1 aBhange, Deu, S.1 aDeshpande, Aparna1 aKulkarni, Mukund, S.1 aGupta, Narendra, M. uhttp://library.ncl.res.in/content/doping-induced-microstructural-textural-and-optical-properties-in2ti1-xvxo5delta-001661nas a2200217 4500008004100000022001400041245012500055210006900180260008000249300001200329490000800341520084700349100002001196700001501216700001601231700001701247700001901264700001701283700001301300856013001313 2010 eng d a1951-635500aDynamic study of N ` N-dimethylparanitroaniline encapsulated in silicalite-1 matrix using neutron spin-echo spectroscopy0 aDynamic study of N Ndimethylparanitroaniline encapsulated in sil aTIERGARTENSTRASSE 17, D-69121 HEIDELBERG, GERMANYbSPRINGER HEIDELBERGcOCT a279-2840 v1893 a

The present work focuses on the dynamic studies of N'N-dimethyl-paranitroaniline (dmpNA) encapsulated in silicalite zeolite. Quasielastic neutron scattering (QENS) experiments are carried out using neutron spin-echo technique. Polarisation of the scattered neutron beam is measured at carefully chosen values of Q = 0.35, 0.9, 1.1 and 1.45 angstrom(-1) at fixed T = 298K and at fixed Q = 0.9 angstrom(-1) at 150, 200, 250 and 298 K. This gives insight into the motion and the related activation energy of the guest dmpNA molecule. The quasielastic signal observed in the present system within the time range considered is due to fast local rotational motions of protons of the end methyl groups. The results are in good agreement with the dynamics of methyl group rotations reported in the literature by back-scattering QENS technique.

1 aBhange, Deu, S.1 aDejoie, C.1 aPorcher, F.1 aMalikova, N.1 aMartinetto, P.1 aDooryhee, E.1 aAnne, M. uhttp://library.ncl.res.in/content/dynamic-study-n-n-dimethylparanitroaniline-encapsulated-silicalite-1-matrix-using-neutron-002162nas a2200217 4500008004100000022001400041245010600055210006900161260007300230300001200303490000800315520133500323653001401658653002701672653003401699100002001733700002001753700002101773700002001794856013001814 2011 eng d a0926-860X00aDirect synthesis of well-ordered mesoporous Al-SBA-15 and its correlation with the catalytic activity0 aDirect synthesis of wellordered mesoporous AlSBA15 and its corre aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUN a176-1840 v4003 a

The synthesis of Al-SBA-15 under milder acidic conditions were made through an adjusting the molar H(2)O/HCl ratio which indicate the formation of Si-O-Al linkages that lead to isomorphous substitution of Si(4+) by some Al(3+) ions. By adjusting the H(2)O/HCl molar ratio, Al gets incorporated into the lattice of SBA-15, which is evidenced by XRD. N(2) adsorption, TEM, (29)Si and (27)Al MAS NMR spectroscopic data. Aluminium incorporated SBA-15 samples retained both structural and textural properties of SBA-15. The (27)Al MAS NMR confirms that a large proportion of the Al is inserted into tetrahedral positions within the framework. The Al(3+) ions could assume a tetrahedral coordination and be part of the hexagonal structure of silica in Al-SBA-15. In the present study, we have examined the effectiveness of Al-SBA-15, as an acid catalyst for the esterification of acetic acid and in benzylation of anisole. The high activity of Al-20 sample in esterification reaction has been attributed to isolated, generally tetrahedrally coordinated, framework Al species. While in benzylation of anisole, the best result was achieved with Al-5 catalyst. The selectivity for benzylanisole increases and that for dibenzylether decreases with increase in the Si/Al ratio of Al-SBA-15. (C) 2011 Elsevier B.V. All rights reserved.

10aAl-SBA-1510aBenzylation of anisole10aEsterification of acetic acid1 aBhange, Pallavi1 aBhange, Deu, S.1 aPradhan, Sivaram1 aRamaswamy, Veda uhttp://library.ncl.res.in/content/direct-synthesis-well-ordered-mesoporous-al-sba-15-and-its-correlation-catalytic-activity-0