Pt Nanoparticle-Decorated Reduced Graphene Oxide Hydrogel for High-Performance Strain Sensor: Tailoring Piezoresistive Property by Controlled Microstructure of Hydrogel

Abstract

A class of conducting reduced graphene oxide hydrogels is prepared with various porosities, surface areas, and electrical conductivities using ethylenediamine (EDA)/functionalized graphene oxide (GO) and ascorbic acid (VC)/GO by hydrothermal method. The microstructure of hydrogels is tailored by changing the composition of materials. It is observed that the conducing network is formed by cross-linked graphene platelets, and the piezoresistive behavior of hydrogels under cyclic compressive strain shows a linear trend up to 6.8% strain when the hydrogel is prepared by adding 5 wt % of EDA in aqueous GO solution. In addition, platinum nanoparticle-decorated (Pt NP-decorated) EDA-GO hydrogel was also prepared, showing greatly improved linear strain range as high as 52.8% with an increase in compressive modulus by 873% because of the multiscale reinforcing mechanism, which is attributed to the strong interaction between Pt NPs and graphene platelets. The piezoresistivity of the hydrogels can be of great intere...