In this work, hybrid catalysts of Fe and Co with five different ratios ((wt/wt) 100Fe, 75Fe-25Co, 50Fe-50Co, 25Fe-75Co, and 100Co) were prepared via the impregnation of the catalyst precursors into a porous alumina substrate. Thereafter, the developed hybrid catalysts were used to synthesize multi walled carbon nanotube (CNT) using the chemical vapor deposition (CVD) method. Synthesized CNTs were melt mixed with a poly(vinylidene fluoride) (PVDF) matrix at different concentrations, ranging from 0.3 wt% to 3.5 wt%, compression molded, and morphologically and electrically characterized. Scanning electron microscopy revealed that 75Fe-25Co had smaller size and narrower particle size distribution compared to the other ratios, leading to the synthesis of CNTs with higher aspect ratio. Thermogravimetric analysis demonstrated that CNT75Fe-25Co had higher carbon purity, as well as enhanced quality and graphitization degree. Transmission electron microscopy and optical microscopy showed superior nanodispersion and microdispersion states for the nanocomposites containing CNT75Fe-25Co, respectively. Electrical conductivity and electromagnetic interference (EMI) shielding effectiveness of the prepared nanocomposites indicated enhanced values for the CNT75Fe-25Co/PVDF nanocomposites. The superior electrical properties of CNT75Fe-25Co /PVDF nanocomposite were ascribed to a combination of high carbon purity, high aspect ratio and high graphitization degree of CNTs combined with a decent dispersion state of CNTs within the PVDF matrix.