Graphene-Oriented Construction of 2D SnS for Methanol Gas-Sensor Application

Group-IV monochalcogenides with unique 2D puckered honeycomb structure (MX, M 1/4 Ge, Sn/X 1/4 S, Se) have a great prospect in the gas-sensor field. Herein, an exploratory study on 2D SnS is synthesized through a solvothermal method, is performed for promising methanol sensor. To break through the inhibition of the general agglomeration and poor conductivity of solvothermal synthesized SnS on gas-sensing performance, a hybrid of SnS@rGO is designed and constructed based on poly(diallyl dimethyl ammonium chloride) (PDDA)-assisted electrostatic self-assembly. With directed growth of SnS on the PDDA-modulated graphene oxide (GO), an expected architecture characterized by well-dispersed loosely arranged SnS nanosheets attaching on the highly conductive rGO is achieved. The unique hybrid architecture and the conductivity modulation of rGO promotes sensing responses and dynamic characteristic of SnS-based sensor toward methanol detection. The achieved SnS@rGO hybrid with less stacking architecture of SnS displays a approximate to 3.3-fold enhancement in gas response to 15 ppm methanol in comparison to the flower-like stacked SnS. The formation mechanism of SnS@rGO hybrid based on the oriented growth of SnS by PDDAmodulated GO is clarified schematically and the response enhancement of the hybrid is demonstrated in terms of the unique architecture and the conductivity modulation.