Fast response paper based visual color change gas sensor for efficient ammonia detection at room temperature.

ABSTRACT: We show that a cheap, disposable type rapid paper sensor (working at room temperature) can be made using perovskite halide CH₃NH₃PbI₃ (MAPI) to detect presence of the toxic ammonia gas (NH₃)by just color change, where the black colored MAPI film (on the paper) changes to yellow color in presence of a very low concentration of NH₃ gas. The sensor can detect presence of NH₃ gas in open or closed atmosphere down to around 10 ppm with a response time of nearly 10 sec which decreases to few seconds when the concentration exceeds 20 ppm. The easy to fabricate sensor paper being a visual sensor does not need any other extra equipment for its operation. The sensor is not sensitive to moisture with RH upto 90% and does not also respond to gases like Methane (CH₄), Nitrous Oxide (N₂O), Carbon dioxide (CO₂) etc in the test chamber each up to a concentration of 500 ppm. Conversion/decomposition of MAPI to PbI₂ on exposure to NH₃ has been proposed as the mechanism of color change and the mechanism has been established using a collection of techniques like XRD, EDX, UV-Visible absorption and Photo Luminescence.

SUBMITTER: Maity A 

PROVIDER: S-EPMC6237894 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature