Analytical Modeling of a Hydrogen Sensor Based on Exfoliated and Reduced Graphene Oxide

Hydrogen can be considered a clean energy carrier with zero carbon emissions, produced from renewable energy sources. However, hydrogen is a highly flammable gas and can form explosive mixtures with oxygen; hence, sensing techniques are essential for timely leak detection. This paper presents the experimental characterization of a hydrogen sensor based on sensing material consisting of thermally exfoliated/reduced graphene oxide (rGO) films deposited on a sensor device by the drop-coating technique. The measurement of changes in electrical resistance due to hydrogen gas exposure operating at different temperatures (27°C, 90°C, and 150°C) is carried out in a gas chamber with a known concentration of hydrogen in constant air flow. In addition, a generalized mathematical formulation is provided for the dependence of hydrogen gas concentration, temperature, and sensor resistance for the hydrogen gas sensor based on exfoliated/reduced graphene oxide.