title: CdO-based nanostructures as novel CO(2) gas sensors.
abstract: Crystalline Cd(OH)(2)/CdCO(3) nanowires, having lengths in the range from 0.3 up to several microns and 5-30 nm in diameter, were synthesized by a microwave-assisted wet chemical route and used as a precursor to obtain CdO nanostructures after a suitable thermal treatment in air. The morphology and microstructure of the as-synthesized and annealed materials have been investigated by scanning electron microscopy, transmission electron microscopy, x-ray diffraction and thermogravimetry-differential scanning calorimetry. The change in morphology and electrical properties with temperature has revealed a wire-to-rod transformation along with a decreases of electrical resistance. Annealed samples were printed on a ceramic substrate with interdigitated contacts to fabricate resistive solid state sensors. Gas sensing properties were explored by monitoring CO(2) in synthetic air in the concentration range 0.2-5 v/v% (2000-50 000 ppm). The effect of annealing temperature, working temperature and CO(2) concentration on sensing properties (sensitivity, response/recovery time and stability) were investigated. The results obtained demonstrate that CdO-based thick films have good potential as novel CO(2) sensors for practical applications.
authors.affiliation: Department of Physics, King College of Technology, Nallur, Namakkal, Tamilnadu-637 020, India.
authors.forename: T
authors.initials: T
authors.lastname: Krishnakumar
authors.forename: R
authors.initials: R
authors.lastname: Jayaprakash
authors.forename: T
authors.initials: T
authors.lastname: Prakash
authors.forename: D
authors.initials: D
authors.lastname: Sathyaraj
authors.forename: N
authors.initials: N
authors.lastname: Donato
authors.forename: S
authors.initials: S
authors.lastname: Licoccia
authors.forename: M
authors.initials: M
authors.lastname: Latino
authors.forename: A
authors.initials: A
authors.lastname: Stassi
authors.forename: G
authors.initials: G
authors.lastname: Neri
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry*; D002245:Carbon Dioxide / Q000032:analysis*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D008872:Microwaves; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology; D010087:Oxides / Q000737:chemistry*; D010316:Particle Size; D013696:Temperature; D013818:Thermogravimetry; D014961:X-Ray Diffraction
chemical_list: D019187:Cadmium Compounds; D010087:Oxides; C029663:cadmium oxide; D002245:Carbon Dioxide