Novel capacitive humidity sensing properties of cobalt chromite nanoparticles based thick film

• Published in: Microchemical journal Vol. 152; p. 104452
• Main Authors: Mahapatra, Preeti Lata, Mondal, Partha Pratim, Das, Sagnik, Saha, Debdulal
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2020
• Subjects: Capacitive sensor; Microporous; Sol-gel; Spinel structure; Thick film; Thick film; Microporous; Capacitive sensor; Sol-gel; Spinel structure
• ISSN: 0026-265X; 1095-9149
• DOI: 10.1016/j.microc.2019.104452

•Preparation of cobalt chromite nanopowder by a facile and cost-effective sol-gel method.•Development of humidity sensor based on tape casted micro porous spinel cobalt chromite thick film.•Developed sensors demonstrate excellent humidity sensing properties.•Sensors exhibit fast response and recovery time with a humidity detection limit from 5–95%RH.•Unravelling of the novel and excellent humidity sensing properties of cobalt chromite spinel.•Sensors are very stable and reusable if regenerated by non-aqueous solvent. Novel and excellent humidity sensing properties of sol-gel prepared spinel cobalt chromite nanoparticles based microporous thick films reported for the first time. Microporous thick film was prepared by sintering a green tape of cobalt chromite prepared by tape casting which was subsequently sandwiched between two parallel silver electrodes to develop a capacitive humidity sensor. Developed sensors demonstrate excellent humidity sensing behavior in the range of 5 to 95% relative Humidity (RH) with an appreciable gain of 3 pF/%RH. Dielectric polarization of moisture molecules absorbed on the CoCr2O4 surface and condensed in the surface pores leads to an appreciable enhancement of dielectric constant hence the sensing properties. Various sophisticated experiments have been carried out to have an insight into its’ physicochemical properties that culminates into the excellent moisture sensing abilities of the sensor. [Display omitted]