High-performance Gas Sensing by Chemically Modified 3D Graphene Hydrogel

For the first time, we develop a high performance, cost-effective gas sensor by exploiting 3D chemically functionalized reduced graphene oxide hydrogel (FRGOH). The self-assembly and chemical modification of 3D FRGOH are realized using hydroquinone molecules in a simple, one-step hydrothermal synthesis process. Compared with an unmodified RGOH counterpart, the chemically derived FRGOH sensor not only displays twofold higher sensitivity in both nitrogen dioxide and carbon dioxide sensing, but also exhibits significantly faster recovery and lower limit of detection (LOD). Importantly, the integrated microheater is employed not only to significantly improve the selectivity of nitrogen dioxide sensing by elevating substrate temperature, but also to accelerate the response and recovery.