High sensitivity self-recovery ethanol sensor based on polyporous graphene oxide/melamine composites

A porous graphene oxide/melamine composite sponge with highly dispersed graphene oxide sheets are prepared for high-sensitivity and self-recovery sensor of ethanol. The combination of graphene oxide and melamine with large surface area leads to sensitive to surface absorption due to avoiding the overlap of the graphene oxide sheets assembled in the sponge scaffold. The sensor exhibits a highly sensitive ethanol detection based on dielectric loss with two orders of magnitude change at 1670 ppm ethanol concentration, which is much higher than other sensors based on resistance or electrical conductivity. The detection limit is 70 ppm, which can be decreased by increasing the electrode area. The remarkable sensor performance is linked with the local conductive networks and relaxation polarization from introduction of polar functional groups in the sponges. Furthermore, the sensor has shape self-recovery capability due to its unique three-dimensional interconnect porous structure, which can be used to fabricate electronic nose of human-like robot closer to reality. (c) 2018 Elsevier Ltd. All rights reserved.