An enhanced gas sensor based on SiO2@mesoporous MCM-41 core–shell nanocomposites for SO2 visual detection

• Published in: Analyst (London) Vol. 145; no. 12; pp. 4352 - 4357
• Main Authors: Yang, Ji, Cheng, Fuqiang, Zhu, Zuogang, Feng, Jinsheng, Xue, Min, Meng, Zihui, Qiu, Lili
• Format: Journal Article
• Language: English
• Published: London Royal Society of Chemistry 21.06.2020
• Subjects: Colorimetry; Detection; Gas sensors; Hexamine; Nanocomposites; Silicon dioxide; Sulfur dioxide; Zinc chloride
• ISSN: 0003-2654; 1364-5528
• DOI: 10.1039/d0an00621a

A colorimetric sulfur dioxide (SO2) gas sensor based on a core–shell composite was developed. The composite was fabricated with a silicon dioxide core and a mesoporous MCM-41 shell (SiO2@MCM-41), and further loaded with a 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 a gas detection tube (GDT), respectively. Each of these sensing configurations showed a distinct color change from pale yellow to red, which indicates good potential for naked-eye detection of SO2. The limit of detection (LOD) is 2 ppm for SiO2@MCM-41 discs, which indicates high sensitivity to SO2. The performance of GDT suggested a linear relationship between the SO2 concentration and the response length of the red portions in a range of 100–1000 ppm. This work shows promising potential of SiO2@MCM-41 as an easy, effective and rapid response sensing material for the in situ detection of SO2.