Chemoresistive gas sensors based on two-dimensional (2D) materials including graphene-based materials have attracted significant research interest owing to their potential use in next-generation technologies including the Internet of Things (IoT). The functionalization of 2D materials is considered as a key strategy to achieve superior gas sensing properties such as high selectivity, high sensitivity, and reversible response and recovery, because it can modulate the chemical and electrical properties of 2D materials for more efficient gas sensing. Herein, we present a facile solution process and the room temperature gas sensing properties of chemically fluorinated graphene oxide (CFGO). The CFGO sensors exhibit improved sensitivity, selectivity, and reversibility upon exposure to NH3 with a significantly low theoretical detection limit of ∼6 ppb at room temperature in comparison to NO2 sensing properties. The effect of fluorine doping on the sensing mechanism is examined by first-principles calculations based on density functional theory. The calculations reveal that the fluorine dopant changes the charge distribution on the oxygen containing functional groups in graphene oxide, resulting in the preferred selective adsorption and desorption of NH3 molecules. We believe that the remarkable NH3 sensing properties of CFGO and investigation by first-principles calculations would enlarge the possibility of functionalized 2D materials for practical gas sensing applications such as the IoT.
Bibliographical noteFunding Information:
This research was supported by the Basic Science Research Program (2017R1A2B3009135), the Future Material Discovery Program (2016M3D1A1027666), and the Nano Material Technology Development Program (2016M3A7B4910) through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and future Planning and the International Energy Joint R&D Program (20168510011350) of the Korea Institute of Energy Technology Evaluation and Planning (KETEP).
© 2017 The Royal Society of Chemistry.
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)