Sensitive Room-Temperature H2S Gas Sensors Employing SnO2 Quantum Wire/Reduced Graphene Oxide Nanocomposites

Metal oxide/graphene nanocomposites are emerging as one of the promising candidate materials for developing high-performance gas sensors. Here, we demonstrate sensitive room-temperature H2S gas sensors based on SnO2 quantum wires that are anchored on reduced graphene oxide (rGO) nanosheets. Using a one-step colloidal synthesis strategy, the morphology-related quantum confinement of SnO2 can be well-controlled by tuning the reaction time, because of the steric hindrance effect of rGO. The as synthesized SnO2 quantum wire/rGO nanocomposites are spin-coated onto ceramics substrates without further sintering to construct chemiresistive gas sensors. The optimal sensor response toward 50 ppm of H2S is 33 in 2 s, and it is fully reversible upon H2S release at 22 degrees C. In addition to the excellent gas adsorption of ultrathin SnO2 quantum wires, the superior sensing performance of SnO2 quantum wire/rGO nanocomposites can be attributed to the enhanced electron transport resulting from the favorable charge transfer of SnO2/rGO interfaces and the superb transport capability of rGO. The easy fabrication and room temperature operation make our sensors highly attractive for ultrasensitive H2S gas detection with less power consumption.