One-pot synthesis of tin oxide/reduced graphene oxide composite coated fabric for wearable ammonia sensor with fast response/recovery rate

Abstract

By using polyimide (PI) fabric as a flexible substrate, tin dioxide (SnO2)/reduced graphene oxide (rGO) composite coated fabrics (PI-SnO2/rGO) were prepared via electrostatic layer-by-layer self-assembly and in situ hydrothermal method. The morphology and microstructure of PI-SnO2/rGO were characterized by FT-IR, Raman, XPS and SEM, and its ammonia (NH3) sensing performance at room temperature was tested. The results show that the average size of SnO2 nanoparticles in the composite coating is about 3 nm, and there is a strong interfacial interaction between SnO2 and rGO. Consequently, PI-SnO2/rGO exhibits n-type sensing for NH3 with excellent linear response (R2 =0.995) in the range of 50–400 ppm, high sensitivity (5.16 % for 100 ppm NH3), fast response/recovery rate (94 s/57 s) and excellent selectivity. In addition, the sensor exhibits good mechanical robustness. The sensitivity is decreased by only 3 % after 2000 stretches.