Electropolymerization and electrochemical performance of salen-type redox polymer on different carbon supports for supercapacitors

N,N′-ethylenebis(salicylideneaminato) nickel(II), (Ni(salen)), which is the archetype of Schiff base metal complexes, was easily synthesized onto the surface of activated carbon (AC), mesoporous carbon (MC) and multi-walled carbon nanotube (MWCNT) by the route of linear potential sweep, respectively. The microstructure of the poly[Ni(salen)] homogeneously grown on the different carbon supports was evidenced by field emission scanning electron microscopy (FESEM). Growth parameters such as the apparent surface coverage and the doping level were investigated to confirm the effects of supports on the Ni(salen) polymerization. Diffusion coefficient was calculated from the chronoamperometry test to characterize the charge transport ability with the different pore size distributions of the supports, and the result indicates that MWCNT support with abundant macro porous is more active to the growth of the polymer and the charge diffusion. Capacitance performance of the electrodes was discussed by constant charge/discharge and alternating current impedance tests. A 3.79 times capacitance increase of the poly[Ni(salen)] electrode with MWCNT as a support was observed. The exceptional electrochemical properties make the use of MWCNT an attractive support for poly[Ni(salen)] as a supercapacitor material.