Research Seminar of Prof. Liu Chuan and Prof. Wu Jin from Sun Yat-sen University

Lecture Time: 09:00 on 20th November, 2017

Lecture Room: C501 of Science and Innovation Building

Sun Yat-sen University

Improved Gas Sensing Using Three-Dimensional Graphene

Abstract

Graphene (Gr) based gas sensors have attracted widespread research interest because of their potential use in the next generation technologies such as Internet of Things (IoT). Recently, 3D Gr porous structures demonstrate improved gas sensing performance compared with the 2D counterparts due to their unique porous structure with enlarged surface area. We demonstrate a better gas sensing system with 3D Gr synthesized by several different strategies. The 3D reduced graphene oxide hydrogel (RGOH) synthesized by a one-step, hydrothermal, and self-assembly method can be exploited for high-performance NO2 and NH3 sensing. Importantly, an integrated microheater is exploited for the first time to improve the selectivity of NO2 sensing. Compared with an unmodified RGOH counterpart, the chemically functionalized reduced graphene oxide hydrogel (FRGOH) not only displays twofold higher sensitivity in both NO2 and CO2 sensing, but also exhibits significantly faster recovery and a lower limit of detection. The microwave plasma-enhanced chemical vapor deposition (MPCVD) is deployed to synthesize cauliflower Gr for NO2 detection with high performance, including ultrahigh sensitivity (133.2 ppm-1), good selectivity, fast recovery (within 2 s) and reversibility. In addition, 3D spark plasma sintering (SPS)-synthesized, superhydrophobic and hierarchical reduced graphene oxide is exploited for high-performance NO2 detection with good immunity to humidity.