Enhanced H2S gas sensing properties based on SnO2 quantum wire/reduced graphene oxide nanocomposites: Equilibrium and kinetics modeling

SnO2 quantum wire/reduced graphene oxide nanocomposites (SnO2 QW/rGO) were synthesized by a facile one-step hydrothermal method with rGO and SnCl4.5H(2)O as the precursors. The SnO2 QW/rGO nanocomposites well-dispersed in ethanol were spin-coated onto ceramics substrates to construct chemiresistive gas sensors. The H2S-sensing isotherm curves were obtained based on the real-time response curves of the SnO2 QW/rGO gas sensors when operated at different temperatures ranging from 30 degrees C to 70 degrees C, from which the adsorbing/sensing performance of the specific materials were extracted and the kinetic parameters (such as response rate constant k and activation energy Ea) of the sensing-materials were quantitatively modeled. The H2S-sensing mechanism was found to follow Langmuir isotherm and pseudo-first-order model. Compared to pure SnO2 QW sensors, the SnO2 QW/rGO gas sensors exhibited higher sensitivity and faster response rate toward" H2S, which was attributed to its lower activation energy. The SnO2 QW/rGO gas sensors can even detect H2S at room temperature, highly attractive for the detection of H2S detection with lower power consumption. (C) 2017 Elsevier B.V. All rights reserved.