Microwave irradiation-induced palladium nanoparticle-mediated perforation and decoration of reduced graphene oxide nanosheets composite for electrode in supercapacitors

Here, we demonstrate that perforated reduced graphene oxide (rGO) nanosheets can be prepared with the help of palladium nanoparticles using a simple microwave technique and applied as electrode material in supercapacitors (SCs). Palladium nanoparticles-assisted perforated rGO (Pd-p-rGO) nanosheets improve the electrochemical performance of devices by increasing the specific surface area of the material. Multiple characterization techniques, including X-ray diffraction, Raman spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM), confirmed the perforated structure of the rGO nanosheets. SEM and TEM analysis revealed that rGO nanosheets included holes with sizes ranging from 20 to 140 nm. The use of Pd-p-rGO nanocomposites demonstrated high performance in SC tests without the need for chemical or physical activation. At 5 mV/s scan rate in 1 M KOH aqueous solution, the specific capacitance of the electrode material based on Pd-p-rGO nanocomposites reached 666.8 F/g. According to the analysis of cycling stability, the capacitance retention was ~92.5 % after 5,500 cycles at a scan rate of 65 mV/s. Both the high specific surface area and the perforated structure of Pd-p-rGO nanocomposites have been proposed as possible explanations for their exceptional SC performance.