. . . . . . . . . .    ANM 2010     3rd International Conference on Advanced Nano Materials     12-15 September 2010 - Agadir, Morocco Back    Abstract ANMM143 NANOSTRUCTURED PT-RU DECORATED MULTI WALLED CARBON NANOTUBES  BASED HYDROGEN GAS SENSORS Adarsh Kaniyoor and S. Ramaprabhu Alternative Energy and Nanotechnology Laboratory (AENL), Nano Functional Materials Technology Centre (NFMTC), Department of Physics, IIT Madras, Chennai-600036 . In the context of hydrogen based economy, novel high sensitive materials for hydrogen gas flow monitoring and leak detection become essential. Noble metal decorated multi walled carbon nanotubes (MWNTs) are promising nanocomposites for hydrogen gas sensing. However, in this regard, the response of nanostructured bi-metallic alloy decorated MWNTs has yet to be investigated. Herein we present our studies on the hydrogen sensing response of Pt-Ru bi-metallic alloy decorated on MWNTs (Pt-Ru/MWNTs). MWNTs were synthesized by catalytic chemical vapour deposition (CCVD) of acetylene gas over Ni based alloy hydride catalyst in the temperature range 700-800˚C. Pt and Ru nanoparticles with an atomic ratio of 1:1 were decorated over MWNTs by chemical reduction from their precursor salts. This nanocomposite was characterized by X-ray diffractometry (XRD), Raman and Fourier transform-Infra red spectroscopy (FT-IR), Energy Dispersion by X-Rays (EDX), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM).  Thick films of Pt-Ru/MWNTs were then fabricated by a simple drop casting technique and its hydrogen sensing response was studied in a house developed hydrogen sensor test station.  Hydrogen concentration was varied in the near lower flammability limit (1 to 4 vol. % in air) and the variation in sensitivity, response time and recovery time of the sensor was investigated. Variation in sensor properties with temperature up to 150°C was also investigated. The adsorption kinetics could be explained by invoking the Avraami-Erofeev theory. The results have been discussed at length. . © nanoAC . . . . . . . . . .

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