Synergistic effects in hybrid buckypapers of graphene nanoplatelets and carbon nanotubes: processing and performance

Hybrid buckypapers (BPs) composed of graphene nanoplatelets (GNPs) and carbon nanotubes (CNTs) hold great potential for applications in flexible electronics, electromagnetic shielding, and energy storage. In this study, hybrid BPs were fabricated and characterized to evaluate their structural, thermal, and electrical properties. Hybrid BPs with varying GNP/CNT mass ratios (0/100, 25/75, 50/50, 75/25, 85/15, 90/10, and 95/5 wt%) were prepared via vacuum-assisted filtration of well-dispersed aqueous suspensions stabilized by surfactants. The resulting hybrid GNP/CNT BPs were dried and subjected to post-treatment processes to enhance structural integrity and electrical performance. Characterization techniques included scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR), Raman spectroscopy, thermogravimetric analysis (TGA), nitrogen adsorption/desorption isotherms, and impedance spectroscopy (IS). The hybrid GNP/CNT BPs exhibited electrical conductivities comparable to conventional CNT-based BPs. At GNP concentrations of 25 to 50 wt%, electrical conductivity values approached those of CNT-based BPs, while at GNP concentrations between 75 and 90 wt%, a slight increase in conductivity was observed (171%). These results highlight a synergistic effect at lower CNT concentrations, where the combination of CNTs and GNPs enhances conductivity. The findings suggest that optimal conductivity is achieved through a balanced incorporation of both materials, offering promising prospects for advanced BP applications.