FABRIKASI DAN KARAKTERISASI HIDROGEL POLYVINYL ALCOHOL-REDUCED GRAPHENE OXIDE UNTUK APLIKASI ELEKTRODA SUPERKAPASITOR FLEKSIBEL

Abstract

Hydrogel supercapacitors have undergone rapid development, particularly reduced graphene oxide-based. Herein, flexible polyvinyl alcohol-reduced graphene oxide hydrogel was synthesized through the freeze-thaw cycle. Various analyses were performed to evaluate the hydrogel's properties. XRD showed that higher rGO content led to an increased amorphous phase. The FTIR spectra possess an O-H absorption band at 3550-3200 cm-1. FE-SEM revealed that the porosity of the hydrogel lies in the range of 60-70%. Raman revealed that the intensity ratio of ID and IG of PVA-rGO 0.11 is 1.653, implying a transition from a crystalline to an amorphous structure. Incorporation of rGO enhances the wettability of hydrogel, the water contact angle decreases from 29.62° to 18.004°. Differential scanning calorimetric and thermogravimetry analysis showed that the melting temperature decreased as increasing the rGO content, indicating hydrogel exhibited a more amorphous structure. PVA-rGO hydrogel exhibits good electrochemical properties of the double-layer capacitor with a maximum capacitance of 0.0026 mF.cm-2 at a scan rate of 20 mV.s-1. The Nyquist plot showed that the interfacial resistance decreases with increasing rGO content, from 50,500 to 24,713 Ω. The breaking strength of hydrogel increased from 106.98% to 114.74%. These encouraging results demonstrate PVA-rGO hydrogel is promising electrode material for supercapacitor application.