Journal
ACS APPLIED MATERIALS & INTERFACES
Volume 13, Issue 1, Pages 1956-1966Publisher
AMER CHEMICAL SOC
DOI: 10.1021/acsami.0c18582
Keywords
silica; trimethoxyoctadecylsilane; gas sensor; relative selectivity; steric effect
Funding
- Open Project of State Key Laboratory of Industrial Vent Gas Reuse [SKLIVGR-SWPU-2020-01]
Ask authors/readers for more resources
In this study, Trimethoxyoctadecylsilane (OTMS) was used to decorate mesoporous silica to enhance gas selectivity, with a quartz crystal microbalance employed to measure gas-sensing properties. The crucial role of OTMS content in affecting silica's adsorption capacity and selectivity was highlighted, and a three-state mechanism was proposed to explain the sensing mechanism of OTMS-decorated silica.
Trimethoxyoctadecylsilane (OTMS) was successfully used to decorate mesoporous silica with a self-assembly method to enhance the relative gas selectivity. A quartz crystal microbalance was employed to measure the gas-sensing properties. The content of OTMS was the crucial factor that greatly affected the adsorption capacity (q) of silica, which could be converted to relative selectivity (S) to study the sensing mechanism. With increasing OTMS content, q was far higher for small-molecule gases compared to volatile organic compounds (VOCs), which could be explained by the polarity of the bonding objects, and S reached a maximum value of 45.71%. When exposed to VOCs, S was always greater than 0 among the three alcohols. The sensing mechanisms of undecorated silica and OTMS-decorated silica were quite different; the three-state mechanism was proposed to explain the sensing mechanism of OTMS-decorated silica. When exposed to small-molecule gases, the atoms that bonded with carbon atoms on OTMS greatly influenced q. With increasing OTMS content, the bonding energy of OTMS with CO2 was far less than that with other molecules, resulting in a relative selectivity as high as 38.69%. Furthermore, macroperformance and microproperties were combined in three-dimensional coordinates, which could be applied to predict the sensing performance of silica.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available