Preparation and electrochemical performance of 1,4-naphthaquinone-modified carbon nanotubes as a supercapacitor material

Abstract Carbon nanotubes (CNT) are potential electrode materials for supercapacitors due to their high specific surface area and excellent conductivity. Here, 1,4-Naphthoquinone (NQ)-modified nitrogen-oxygen co-doped carbon nanotubes (NQ/N–O-CNT) were synthesized. The influences of NQ modification on the structure and electrochemical properties of as-prepared materials were examined by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron microscopy (XPS), scanning electron microscopy (SEM), galvanostatic charge/discharge (GCD), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). By the modification process, nitrogen and oxygen were effectively doped into CNT, causing an increase in nitrogen- and oxygen-containing functional groups, which was proved by XPS and FTIR. The effective debundling of CNT and the presence of densely packed globular structures on the surface of individual nanotubes was confirmed by SEM. And benefited from the reversible redox reaction of NQ, the specific capacitance of NQ/CNT composites can reach up to 143.68 F g −1 , which is 4.5 times higher than that of CNT (25.78 F g −1) , demonstrating quinone organic compounds can serve as a sustainable pseudocapacitor material for high-performance supercapacitors. After 3000 cycles, the specific capacitance is still 83.6% of its original value.