Synergistical enhancement of the electrochemical properties of lignin-based activated carbon using NH3·H2O dielectric barrier discharge plasma

Abstract

NH3·H2O dielectric barrier discharge (DBD) plasma was applied in lignin-based activated carbon (LCA) to enhance its electrochemical properties. X-ray photoelectron spectroscopy (XPS), electron spin resonance spectrometry (ESR), automated surface area and pore size analysis, X-ray diffraction (XRD) and Raman spectroscopy (Raman) were performed on LCA and LCANH (LCA treated by NH3·H2O DBD plasma) in order to reveal the changes in physical and chemical structures. An electrochemical workstation was used to investigate the electrochemical properties of LCA and LCANH. The results showed that both nitrogen-containing and oxygen-containing chemical groups were incorporated into the carbon surface after plasma treatment. In addition, the specific surface area and micropores volume of LCANH were 21.7% and 8.5% higher than that of LCA. These facts synergistically enhance the electrochemical properties of activated carbon, allowing it to demonstrate a specific capacitance of 271.7 F g-1 for LCANH at a current density of 5 A g-1, which are 74.2% higher compared to LCA.