Enhanced gas sensor based on SiO2@mesoporous MCM-41 core-shell nanocomposites for SO2 visual detection
A colorimetric sulfur dioxide (SO2) gas sensor based on a core-shell composite was developed. The composites was fabricated by a silicon dioxide core with a mesoporous MCM-41 shell (SiO2@MCM-41), and further loaded with the mixture of zinc chloride (ZnCl2), sodium nitroprusside (SNP) and hexamine as an SO2 indicator. The sensing properties of SiO2@MCM-41 toward SO2 were measured in solid powder, discs and gas detection tube (GDT), respectively. Each of these sensing configurations showed distinct color change from pale yellow to red, which indicates a good potential for SO2 naked-eye detection. The limit of detection (LOD) is 2 ppm for SiO2@MCM-41 discs, which exihibited high sensitivity to SO2. And the performance of GDT suggested a linear relationship between SO2 concentration and the response length of the red portions in the range of 100-1000 ppm. This work shows promising potential of SiO2@MCM-41 as an easy, effective and rapid response sensing material for SO2 in-situ detection.
- This article is part of the themed collection: Analytical Nanoscience