This research introduces an innovative approach for evaluating the degree of densification of carbon nanotube (CNT) sheets produced through direct spinning and subsequently treated with organic solvent (specifically ethanol). Analysis of the morphological features of the CNT sheets from the FE-SEM image affirms that the sheet’s structure becomes more densified following the treatment. Based on this, the treated CNT sheet was comprehensively evaluated using Raman spectroscopy. The results indicate a downward shift in the G′ band, signifying the densification of the CNT sheet’s structure due to the C–C bond weakening by the cohesive force. Following ethanol treatment, the CNT sheet exhibited enhanced electrical conductivity and tensile strength, measuring approximately 1.7 × 105 S m− 1 and 138.7 MPa, respectively, a remarkable improvement of roughly 300% compared to the untreated CNT sheet. This study underscores the efficacy of Raman spectroscopy as a powerful tool for assessing the densification of CNT sheets.

Nowadays, variable materials have been investigated to find alternative lightweight conductors instead of copper because copper has a relatively high density. Carbon nanotube (CNT) is one of the most suitable materials as an alternative conductor to Cu, thanks to its high conductivity. In addition, CNT has many other great properties, such as low density, high strength, and high ampacity. However, individual CNT loses some of its performance after the assembly process. Therefore, CNT materials have been electroplated with copper to achieve lighter conductors. In this study, CNT buckypaper (CNTBP) is fabricated using a multi-walled carbon nanotube and copper electroplated using optimizing electrolyte with the help of additive chemicals such as accelerator and suppressor. Furthermore, the effect of hydrochloric acid in the electrolyte on the electroplating of CNTBP is observed. The results show that HCl in electrolyte enhances the effectiveness of additive chemicals and provide a well-plated CNTBP@Cu composite. The composite in this study is expected to be used in various areas.