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

Abstract SnO 2 quantum wire/reduced graphene oxide nanocomposites (SnO 2 QW/rGO) were synthesized by a facile one-step hydrothermal method with rGO and SnCl 4 . 5H 2 O as the precursors. The SnO 2 QW/rGO nanocomposites well-dispersed in ethanol were spin-coated onto ceramics substrates to construct chemiresistive gas sensors. The H 2 S-sensing isotherm curves were obtained based on the real-time response curves of the SnO 2 QW/rGO gas sensors when operated at different temperatures ranging from 30 °C to 70 °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 E a ) of the sensing-materials were quantitatively modeled. The H 2 S-sensing mechanism was found to follow Langmuir isotherm and pseudo-first-order model. Compared to pure SnO 2 QW sensors, the SnO 2 QW/rGO gas sensors exhibited higher sensitivity and faster response rate toward H 2 S, which was attributed to its lower activation energy. The SnO 2 QW/rGO gas sensors can even detect H 2 S at room temperature, highly attractive for the detection of H 2 S detection with lower power consumption.