Ethanol and hydrogen sensors based on ZnO nanoparticles and nanowires.
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.
Rout
Chandra Sekhar
CS
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.
Raju
A R
AR
Govindaraj
A
A
Rao
C N R
CN
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*
D046911:Macromolecular Substances; D000431:Ethanol; D006859:Hydrogen; D015034:Zinc Oxide