Highly Sensitive, Room Temperature Methane Gas Sensor Based on Lead Sulfide Colloidal Nanocrystals

摘要

A solid-state methane gas sensor based on PbS colloidal nanocrystals has been fabricated and tested for the first time. PbS nanoparticles have been synthesized during an all-chemical process and its X-ray diffraction (XRD) pattern has been analyzed to verify the quality and estimate the particle size of produced nano-powder. TEM microscopy and size estimation by XRD analysis both confirm the production of 40-nm PbS nanoparticles. The sensor was fabricated by the drop casting method on interdigitated electrodes and tested at different conditions. The best achieved sensitivity was 47.6% for 5% methane concentration at room temperature. A comprehensive discussion on sensing mechanism, temperature dependence, and sensor's benefits is also provided in this paper. The sensor has the benefit of room temperature detection and being highly sensitive. Moreover, the sensor's detection range is 1%–5% which is of superior importance in air quality monitoring and safety control systems in industrial environments to prevent suffocation and explosion.