Synthesis of silver nanoparticles by using fungi and synthesis of their nanocomposites for supercapacitor applications

Supercapacitors have received substantial interest due to their capacity for high-power delivery, extended cycle life, and environmental compatibility. These devices effectively bridge the energy-power disparity between conventional capacitors, which exhibit high power density, and fuel cells/batteries, renowned for their high energy density. In this study, three types of fungi were used to synthesize AgNPs through different methods. The resulting AgNPs were utilized to synthesize graphene oxide (GO) starting from graphite, which was then reduced to reduced graphene oxide (rGO) using a microwave method. The synthesis of binary rGO/AgNP and ternary rGO/AgNP/polyaniline (PANI) nanocomposites were performed in more detail. Silver nanoparticles were synthesized via a biosynthesis method using three different fungal species (Porcini mushroom, Kanlıca mushroom, and Sığır dili mushroom) and silver nitrate. The synthesized AgNPs were used to produce rGO/AgNP and rGO/AgNP/PANI nanocomposites, which were characterized using Scanning Electron Microscopy with Energy-Dispersive X-ray analysis (SEM-EDX), Fourier Transform Infrared Spectroscopy (FTIR), and Thermogravimetric Analysis (TGA-DTA). The composite materials containing silver nanoparticles were then assembled into supercapacitor devices using 2032 coin cells, and their electrochemical performance was evaluated through cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) measurements. Stability tests were conducted over 1000 cycles using the CV method at a scan rate of 100 mV/s.