Ambient temperature operable Bi-Co ferrite NO2 sensors with high sensitivity and selectivity. (July 2019)

• Record Type: Journal Article
• Authors: Mutkule, Sandesh U.; Tehare, Kailas K.; Gore, Shyam K.; Gunturu, Krishna Chaitanya; Mane, Rajaram S.
• Is Part Of: Materials research bulletin. Volume 115(2019)
• Page Start: 150
• Page End: 158
• Publication Date: 2019-07
• Subjects: A. Semiconductors -- B. Sol-gel chemistry -- C. X-ray differaction -- C. TEM -- D. Lectrical properties; Materials -- Periodicals; Crystal growth -- Periodicals; Matériaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Crystal growth; Materials; Periodicals; 620.11
• DOI: 10.1016/j.materresbull.2019.03.012
• Languages: English
• ISSNs: 0025-5408

Abstract

Graphical abstract: Bi-CoFe2 O4 acts as p -type behaviour at lower concentration and n -type behaviour at higher concentration of NO2 gas. Highlights: Bi-Co ferrite sensor is synthesized by sol-gel auto-combustion method. The Bi-Co ferrite sensor has exhibited a response of 34% @200 ppm of NO2 which even after 30 days has remained relatively unchanged. Proposed sensing mechanism in accord to experimental findings. Abstract: The sol-gel chemical synthesis, reaction mechanism, structural, morphological and elemental scanning measurements of bismuth (Bi 3+ )-doped spinel cobalt ferrite (Bi-Co ferrite) film sensors are explored. The gas sensor studies of Bi-Co ferrite sensors performed on methanol, ethanol, hydrogen sulphide, ammonia and nitrogen dioxide (NO2 ) gases at 230 °C as operating temperature where, Bi-Co ferrite sensors are extremely selective towards NO2 gas compared with other gases which is attributed to its high electron donating power. Furthermore, a small 31/29 s response/recovery time value and low detection limit of 25 ppm are evidently been proved its practical application potential. These results helped us to understand the sensing mechanism in Bi-Co ferrite sensors and provided a hint for tuning the conductivity/resistance of metal oxide semiconductor-based gas sensors.