HFIP‐Functionalized Co3O4 Micro‐Nano‐Octahedra/rGO as a Double‐Layer Sensing Material for Chemical Warfare Agents1. Issue 51 (13th August 2019)

• Record Type: Journal Article
• Authors: Alali, Khaled Tawfik; Liu, Jingyuan; Chen, Rongrong; Liu, Qi; Zhang, Hongsen; Li, Jundong; Hou, Jindi; Li, Rumin; Wang, Jun
• Is Part Of: Chemistry. Volume 25:Issue 51(2019)
• Page Start: 11892
• Page End: 11902
• Publication Date: 2019-08-13
• Subjects: Co3O4 -- dimethyl methyl phosphonate -- gas sensors -- hexafluoroisopropanol -- organic–inorganic composites; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201901435
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: Semiconductor metal oxides (SMO)‐based gas‐sensing materials suffer from insufficient detection of a specific target gas. Reliable selectivity, high sensitivity, and rapid response–recovery times under various working conditions are the main requirements for optimal gas sensors. Chemical warfare agents (CWA) such as sarin are fatal inhibitors of acetylcholinesterase in the nerve system. So, sensing materials with high sensitivity and selectivity toward CWA are urgently needed. Herein, micro‐nano octahedral Co3 O4 functionalized with hexafluoroisopropanol (HFIP) were deposited on a layer of reduced graphene oxide (rGO) as a double‐layer sensing materials. The Co3 O4 micro‐nano octahedra were synthesized by direct growth from electrospun fiber templates calcined in ambient air. The double‐layer rGO/Co3 O4 ‐HFIP sensing materials presented high selectivity toward DMMP (sarin agent simulant, dimethyl methyl phosphonate) versus rGO/Co3 O4 and Co3 O4 sensors after the exposure to various gases owing to hydrogen bonding between the DMMP molecules and Co3 O4 ‐HFIP. The rGO/Co3 O4 ‐HFIP sensors showed high stability with a response signal around 11.8 toward 0.5 ppm DMMP at 125 °C, and more than 75 % of the initial response was maintained under a saturated humid environment (85 % relative humidity). These results prove that these double‐layer inorganic–organic composite sensing materials are excellent candidates to serve as optimal gas‐sensing materials. Abstract : Sensing double : Double‐layer sensing materials consisting of HFIP‐functionalized Co3 O4 nm–μm octahedra and reduced graphene oxide (rGO) were developed as a highly selective DMMP (dimethyl methyl phosphonate, sarin simulant) sensor (see figure). HFIP (hexafluoroisopropanol) groups enhanced the selectivity for DMMP owing to hydrogen bonding, and the rGO layer accelerated the charge carriers' mobility and avoided grain boundary poisoning.