Systematic optimization of high-throughput microwave-assisted hydrothermal synthesis of reduced graphene oxide for electrochemical energy storage applications
Adissu Getahun Adugna, Addisu Alemayehu Assegie, Molla Asmare Alemu
Abstract
• Microwave-assisted hydrothermal technique ensures defect-free, scalable, and environmentally friendly conductive rGO electrode in 5 minutes manufacturing, preserving structural integrity • Optimal synthesis occurs at 300 W, 120-140°C, and 5 minutes, balancing deoxygenation and morphology retention. • UV-Vis, FTIR, and TGA tests demonstrate that rGO restores sp², removes oxygen, and has higher thermal stability. • BET study indicates a large surface area (845.6 m²/g) with hierarchical mesoporosity suitable for electrochemical devices. • The MAH technique Reduced graphene oxide (rGO) is a promising next-generation material for electrochemical energy storage because of its high electrical conductivity, mechanical stability, tailored porosity, and large surface area. However, traditional synthesis methods are often environmentally harmful, limited in scalability, and require significant energy and time. Therefore, this study introduces an optimized microwave-assisted hydrothermal method for the rapid, energy-efficient, and sustainable production of rGO under different conditions. The study systematically optimized the key experimental parameters, including microwave power, reaction temperature, and time, are. Accordingly, the optimum results are achieved at 300 W, 140 °C, and 5 min, yielding rGO with a high reduction efficiency of 94.56 wt%, a red shift in UV-Vis absorption to 268 nm, and effective removal of oxygen functionalities. The rGO also exhibited a high specific surface area of 845.6 m²/g, a mesoporous structure, strong thermal stability with 80% residual mass up to 480 °C, and improved electrical conductivity (5.32*103S/m). Electrochemical tests showed effective charge transport, low interfacial resistance (Rs = 1490.86 mΩ, Rct = 727.42 mΩ), and reversible redox activity (Ipa/Ipc =0.9304), confirming its suitability for use in supercapacitors and batteries. Compared to traditional chemical synthesis methods, the microwave-assisted hydrothermal process offers faster production, greener synthesis, and adjustable properties for high-performance energy-storage devices.