Carbonized wood cell chamber-reduced graphene oxide@PVA flexible conductive material for supercapacitor, strain sensing and moisture-electric generation applications

Abstract Wood, as a kind of biomass material, has potential application value in many aspects. In this paper, we designed and prepared a carbonized wood cell chamber-reduced graphene oxide@PVA (CWCC-rGO@PVA) composite material with high specific capacitance, high flexibility, deformability and power generation ability from ambient water using carbonized wood cell chamber (CWCC) as the substrate. GO, as an intermediate product, binds with CWCC in the form of C–C bonds, and the as-obtained intermediate product CWCC-rGO combines with PVA to form hydrogen bonds. The resultant final hybrid CWCC-rGO@PVA shows outstanding electrochemical performance including a high specific capacitance of 288F g−1, capacitance retention of 91%, energy density of 36 Wh kg−1 and power density of 3600 W kg−1. In addition, PVA not only contributes to the high flexibility and deformability of the CWCC-rGO@PVA hybrid, but also has abundant free protons that endow the composite with sensitive sensing properties, so it can serve as a sensor to detect physiological signals of human movement. More importantly, the hydroxylates rich in CWCC-rGO-PVA form hydrogen bonds with the water in the ambient environment, generating a current of up to 5.7 μA under the action of the concentration gradient, which indicates that the CWCC-rGO@PVA can generate electricity by water.