Beneficial effect of Pd and MWCNT co-loading in SnO2 nanoparticles towards the low temperature detection of n-butane gas: synergistic effect on sensing performance

Abstract

A significant enhancement in sensor response and the lowering of operating temperature towards the detection of n-butane gas have been achieved by compositing SnO₂ with a small amount of multi-walled carbon nanotubes (MWCNTs) and Pd. The sensor nanomaterial was prepared by a facile chemical route and characterized by multiple sophisticated techniques, viz., TGA, XRD, TEM, HR-TEM, and I–V. The thick film, chemiresistive sensor was fabricated following the Taguchi model. While Pd induces chemical sensitization, both Pd and MWCNTs enhance the depletion layer thickness in SnO₂ nanoparticles, leading to enhanced sensor response (93% to 2000 ppm n-butane), fast response time (2 s), repeatability, and stability. This sensor is suitable for applications in coal mines, oil refineries, LPG processing and storage plants, etc.