On‐Chip Tailorability of Capacitive Gas Sensors Integrated with Metal–Organic Framework Films. Issue 40 (30th July 2019)

• Record Type: Journal Article
• Authors: Yuan, Hongye; Tao, Jifang; Li, Nanxi; Karmakar, Avishek; Tang, Chunhua; Cai, Hong; Pennycook, Stephen John; Singh, Navab; Zhao, Dan
• Is Part Of: Angewandte Chemie international edition. Volume 58:Issue 40(2019)
• Page Start: 14089
• Page End: 14094
• Publication Date: 2019-07-30
• Subjects: capacitive sensors -- coordinatively unsaturated metal sites -- in situ film growth -- metal–organic frameworks -- on-chip tailorability; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201906222
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Gas sensing technologies for smart cities require miniaturization, cost‐effectiveness, low power consumption, and outstanding sensitivity and selectivity. On‐chip, tailorable capacitive sensors integrated with metal–organic framework (MOF) films are presented, in which abundant coordinatively unsaturated metal sites are available for gas detection. The in situ growth of homogeneous Mg‐MOF‐74 films is realized with an appropriate metal‐to‐ligand ratio. The resultant sensors exhibit selective detection for benzene vapor and carbon dioxide (CO2 ) at room temperature. Postsynthetic modification of Mg‐MOF‐74 films with ethylenediamine decreases sensitivity toward benzene but increases selectivity to CO2 . The reduced porosity and blocked open metal sites caused by amine coordination account for a deterioration in the sensing performance for benzene (by ca. 60 %). The enhanced sensitivity for CO2 (by ca. 25 %) stems from a tailored amine–CO2 interaction. This study demonstrates the feasibility of tuning gas sensing properties by adjusting MOF–analyte interactions, thereby offering new perspectives for the development of MOF‐based sensors. Abstract : When the chips are down : Tailorable on‐chip capacitive gas sensors, integrated with in‐situ‐grown Mg metal–organic framework (Mg‐MOF‐74) films, detect benzene vapor and CO2 selectively at room temperature. The sensing characteristics of the gas sensor are altered by postsynthetic modification of the MOF with ethylenediamine, which affects the interactions between the MOF and the analyte.