Dependence of sheet resistance on dispersion of multi-walled carbon nanotubes grown using size-controlled catalyst particles

Graphical abstract: Nucleation and growth of MWCNTs obtained from different catalyst size. - Highlights: • Catalyst-assisted MWCNT networks were successfully synthesized. • The MWCNT sizes varied according to initial catalyst particle sizes. • The MWCNT sheet resistance values were estimated with a four-point probe. - Abstract: Catalyst-assisted synthesis of multi-walled carbon nanotube (MWCNT) networks was successfully realized by controlling the catalyst particle size with and without post annealing. The sizes of ternary composite catalyst synthesized from spray pyrolysis method varied with different partial pressures and post-annealing. Various-sized MWCNT networks corresponding to individual catalyst sizes were produced through chemical vapor deposition technique. To investigate the dispersion of MWCNTs with respect to catalyst particle size, particle size analyses, scanning electron microscopy, and transmission electron microscopy were performed. In addition, the sieve shaker with 250 mesh were also used for evaluation of correlation between the MWCNTs networks and catalyst sizes. For electrical properties of the samples, MWCNT sheet resistance values were estimated with a four-point probe. These values were used to establish the optimal dispersion of MWCNTs needed to yield optimal carrier density and mobility.