title: Ethanol and hydrogen sensors based on ZnO nanoparticles and nanowires.
abstract: Hydrogen sensing characteristics of thick films of nanoparticles of ZnO and 3% Mn or Co doped ZnO with and without impregnation of 1% Pt have been investigated over a wide concentration range. The sensor characteristics of the Pt impregnated ZnO and 3% Mn or Co-doped ZnO nanoparticles are found to be excellent with the sensitivity reaching values in the 1000-1500 range for 1000 ppm of H2 at 125 degrees C or lower. The sensitivity is quite high even for 10 ppm of H2. The response and recovery times are generally less than 10 s in the region of high sensitivity. These films exhibit very good sensing characteristics for ethanol, the sensitivity being well above 2000 at 50 degrees C for 1000 ppm of vapour. Nanowires of Pt-impregnated ZnO also exhibit satisfactory sensing characteristics, but the values of the sensitivity are somewhat lower. Humidity has negligible effect on the performance of these sensors.
authors.affiliation: Chemistry and Physics of Materials Unit, DST Unit on Nanoscience and CSIR Centre of Excellence in Chemistry, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bangalore 560064, India.
authors.forename: Chandra Sekhar
authors.initials: CS
authors.lastname: Rout
authors.forename: A R
authors.initials: AR
authors.lastname: Raju
authors.forename: A
authors.initials: A
authors.lastname: Govindaraj
authors.forename: C N R
authors.initials: CN
authors.lastname: Rao
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D003460:Crystallization / Q000379:methods; D004559:Electric Wiring / Q000295:instrumentation / Q000379:methods; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D000431:Ethanol / Q000032:analysis* / Q000737:chemistry; D006859:Hydrogen / Q000032:analysis* / Q000737:chemistry; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods; D010316:Particle Size; D013499:Surface Properties; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D046911:Macromolecular Substances; D000431:Ethanol; D006859:Hydrogen; D015034:Zinc Oxide