Development of a luminescent gas sensor based on sulfur quantum dots (SQDs) for ethyl mercaptan detection

This research describes the development of a luminescent gas sensor using sulfur quantum dots (SQD’s) and an LED, demonstrating the potential of s-dots for rapid and sensitive detection of gases like ethyl mercaptan. The study showcases a low-cost and efficient system for gas detection, utilizing the properties of SQD’s deposited on the LED surface and capture of luminescence variation by a cheap photoresistor. Transmission electron microscopy (TEM), X ray diffraction (XRD), Fourier Transform Infrared (FTIR), UV–vis and photoluminescence characterization technique were used. TEM results showed a nearly spherical-shape and an average size distribution of 2.9 ± 0.02 nm. Characteristic signals of vibrational modes S-S and S O bonds were identified through FTIR. XRD revealed the semi crystalline nature sample’s, with sharp peaks indicating the presence of precursor sulfur and its oxidized compounds alongside a broad band centered at 20°. The tests with the gas sensor for ethyl mercaptan proved highly effective for detecting between 0.5 and 7.0 ppm range, with a response and recovery time of 91 and 31 s, respectively.