III International Conference

PP-I-30STRUCTURE OF PHOTOCATALYTIC NANOCOMPOSITES BASED ONMOLYBDENUM OXIDE, TITANIA AND POLY-p-XYLYLENELobanov A.V., Golubeva E.N., Pivkina A.N. 1 , Zavyalov S.A. 2 , Gainutdinov R.V. 3 ,Schoonman J. 4Lomonosov Moscow State University, Moscow, Russia1 N.N. Semenov Institute of Chemical Physics, Russian Academy of Science, Moscow, Russia2 Karpov Institute of Physical Chemistry, Moscow, Russia3 Shubnikov Institute of Crystallography, Russian Academy of Science, Moscow, Russia4 Delft University of Technology, Delft, NetherlandsE-mail: avlobanov@mail.ruNano-composites based on poly-p-xylylene and oxides of molybdenum and titania weresynthesized. Their surface morphology and nature of paramagnetic centers were studied.Nano-structured composites of polymers doped with different metal oxides and organicdyes are advanced photocatalytic systems. Furthermore these composites hold much promisefor creation of novel electrodes and sensors. In this report we present our data on the synthesisof poly-p-xylylene (PPX) composites containing nano-particles of molybdenum and titaniaoxides and the study of their surface morphology by AFM and paramagnetic centers byUV-VIS and ESR spectroscopy.The synthesis of composites was carried out by co-condensation technique of MoO 3 , Tiand p-xylylene in vacuum onto quartz plates and lavsan films cooled by liquid nitrogen.When heating to room temperature and storing on-air the monomer polymerization and Tioxidation take place.Thin films prove to consist of PPX globules of 100-200 nm of spherical shape, which arecovered with metal oxide nano-particles of 5-20 nm. The higher evaporation temperature, the lessare dimensions of the particles. There is weak signal with g-tensor ca. g e in ESR spectra oftitanium oxide/PPX nano-composites. This signal is related to either F-centers or carbon-centers.Doping of phthalocyanine results in the stabilization of Ti 3+ . It turned out, that ESR spectra ofmolybdenum oxide/PPX and molybdenum oxide/titania/PPX nano-composites include intensenarrow signal with g~g e and axially symmetric signal of Mo 5+ with g ║ = 1.860, g ⊥ = 1.929.Absorption in 600-800 nm characteristic for hetero-valenced molybdenum oxides is observed inelectronic spectra. Addition of titania raises content of impurity ions Mo 5+ . The photochemicalproperties of nano-composites were tested under a visible-light irradiation.The work was supported by INTAS (grant 05-1000005-7667) and RFBR(grant 06-03-32287).62