Green-Scale synthesis of High-Purity Graphene: A novel approach with Dual-Source driven dielectric barrier discharge and electric field coupling

Graphene is crucial for various applications, from improving electronics to advancing energy storage and materials science. The green-scale preparation of high-purity graphene remains a significant challenge. Traditional methods, such as thermal and chemical reduction, suffer from extended reaction cycles, high temperatures, and waste liquid pollution. Low-temperature plasma technology offers an efficient, energy-saving, and environmentally friendly solution for the reduction process. However, a better reduction effect largely depends on low-pressure conditions or the addition of reducing gases. Therefore, this paper proposes a dual-source-driven three-electrode atmospheric pressure dielectric barrier discharge plasma device. By capitalizing on the electric field coupling enhancement resulting from voltage polarity differences between pulse and AC power supplies, we achieve efficient reduction using only argon gas. X-ray Photoelectron spectroscopy reveals a substantial enhancement in the reduction process, with the proportion of C=C/C-C bonds reaching 98.5% after 60 min, a marked improvement of 135.1% compared to the original sample. Concurrently, the proportions of C-O and C=O bonds decrease to below 1%, with removal rates reaching 98.8% and 87.7%, respectively. The overall C/O ratio on the product surface increases from 2.2 to 9.4. Electrochemical performance tests demonstrate significant improvements in conductivity and ion transport rates for the graphene product. Notably, the reduction achieved through this method surpasses most similar approaches utilizing only inert gas at atmospheric pressure, establishing the efficacy of our atmospheric pressure dielectric barrier discharge with added reducing gas.