Abstract
CuO nanosheets, Cr-doped CuO nanosheets, and Cr-doped CuO nanorods were prepared by heating a slurry containing Cu-hydroxide/Cr-hydroxide. Their responses to 100 ppm NO2, C2H5OH, NH3, trimethylamine, C3H8, and CO were measured. For 2.2 at% Cr-doped CuO nanorods, the response (Ra/Rg, Ra: resistance in air, Rg: resistance in gas) to 100 ppm NO2 was 134.2 at 250 °C, which was significantly higher than that of pure CuO nano-sheets (Ra/Rg = 7.5) and 0.76 at% Cr-doped CuO nanosheets (Ra/Rg = 19.9). In addition, the sensitivity for NO2 was also markedly enhanced by Cr doping. Highly sensitive and selective detection of NO2 in 2.2 at% Cr-doped CuO nanorods is explained in relation to Cr-doping induced changes in donor density, morphology, and catalytic effects.
Highlights
Oxide semiconductors have been used to detect oxidizing and reducing gases in a simple and cost-effective manner [1,2,3]
Sensitive and selective detection of NO2 in 2.2 at% Cr-doped CuO nanorods is explained in relation to Cr-doping induced changes in donor density, morphology, and catalytic effects
Various strategies aimed at enhancing gas sensing characteristics such as gas response and selectivity have been reported for n-type oxide semiconductors, which include control of the grain size [6,7], morphologies [8], charge carrier concentration [9], catalytic additive(s) [10], and inter-nanostructure contacts [11] of the sensing materials
Summary
Oxide semiconductors have been used to detect oxidizing and reducing gases in a simple and cost-effective manner [1,2,3]. Sensors 2012, 12 oxide semiconductor gas sensors such as those comprising CuO, NiO, Co3O4, and Cr2O3, the adsorption of negatively charged oxygen forms a hole accumulation layer near the surface. Various strategies aimed at enhancing gas sensing characteristics such as gas response and selectivity have been reported for n-type oxide semiconductors, which include control of the grain size [6,7], morphologies [8], charge carrier concentration [9], catalytic additive(s) [10], and inter-nanostructure contacts [11] of the sensing materials. The main focus of this study was investigating the reasons for the enhanced response and selectivity toward NO2 in relation to the Cr-doping-induced changes in the morphology, surface area, resistance in air, and catalytic property
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
