The detection of volatile organic compounds using a CNPs/polypyrrole-based Solid-State sensor operating at room temperature
Year: 2024
Type: article
Abstract: In this work, we report the use of carbon nanoparticles (CNPs), commonly as carbon soot, as they are prepared from the pyrolysis of lighthouse candle, polypyrrole (PPy) and carbon nanoparticles@polypyrrole (CNPs@PPy) composite sensors to detect volatile organic compounds at room temperature. Five sensors were fabricated wherein the first sensor was made up of PPy only was named sensor 1, sensor 2 was made up of CNPs only; sensor 3 was made up of a 1:1 mass ratio of CNPs@PPy, sensor 4 was made up of a 2:1 mass ratio of CNPs@PPy, and sensor 5 was fabricated using a 3:1 mass ratio of CNPs@PPy respectively. The sensors were tested dynamically using acetone, 2-propanol, ethanol, and mesitylene vapours. Among all the tested sensors, sensor 5 showed improved sensitivity towards the analytes as compared to sensors; sensor 5 showed higher sensitivity towards acetone vapour than 2-propanol, ethanol, and mesitylene vapours because of a changed amount of CNPs within the composite. The response and recovery times of sensor 5 towards acetone vapour were 72 and 110 s, respectively and a limit of detection (LOD) of 1.212 ppm. Sensor 5 showed a slight increase in acetone vapour as humidity increased. The gas sensing mechanism on sensor 5 was studied using an in situ Fourier Transform infrared spectroscopy (FTIR) combined with an LCR meter; basically, the acetone vapour interacts with the solid-state gas sensor supplied with 0.5 V at 25 kHz. The setup confirmed that the acetone completely decomposes into carbon dioxide (CO 2 ). It was also confirmed that the CO 2 band intensity increases as the exposure time between the acetone vapour and the sensor increases. • Carbon soot@Polypyrole composite sensor detects volatile organic compounds at room temperature. • The carbon soot@polypyrrole composite sensor has a fast response and recovery time. • An in situ FTIR-LCR meter was used to study the sensing mechanism for the prepared carbon soot@polypyrrole composite sensors.
Source: Materials Chemistry and Physics
Institutions: University of Johannesburg, University of Pretoria
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $2,990
Funder: University of Johannesburg
OpenAlex ID: W4404626223