▎ 摘 要
The dielectric and electrochemical studies for graphene oxide (GO) incorporated poly(vinyl alcohol)/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PVA/PEDOT:PSS) composites are reported here. A high dielectric constant (epsilon') of 2.45 x 10(4) and dielectric loss (epsilon '') of 1.2 x 10(6) were observed for 1.5 wt.% GO in PVA/PEDOT:PSS at 303 K. This is due to the inter-barrier layer created by GO between PVA and PEDOT:PSS through strong pi-pi interaction between GO and PEDOT:PSS as well as inter/intramolecular hydrogen bonding with PVA. The interaction between GO and PVA/PEDOT:PSS resulted in the formation of rod-like structure of GO/PVA/ PEDOT:PSS composite. A semiconductor-insulator-semiconductor transition was observed in the GO/PVA/PEDOT:PSS composite due to the removal of hydroxyl groups and reduction of GO. An interesting cross-over in epsilon '' was observed at 353 K due to the removal of hydroxyl groups followed by a decrease in epsilon '' with increasing temperature and GO content. Electrochemical studies suggested that composites are pseudocapacitive in nature. Specific capacitance for 3 wt% GO in PVA/PEDOT:PSS (PPGO3) was calculated to be 205 Fg(-1) at 1 Ag-1. Cyclic stability greater than 100% and 99% Coulombic efficiency were observed for PPGO3 at 3 Ag-1 and 3000 charge discharge cycles, respectively.