Nanoparticles-enabled low temperature growth of carbon nanofibers and their properties for supercapacitors

Car­bon nano­struc­tures are of great interest for a vari­ety of applic­a­tions, but their cur­rent pro­cessing through­put lim­its their indus­tri­al full scale deploy­ment. This paper presents a cost effect­ive and simple fab­ric­a­tion pro­cess, where ver­tic­ally aligned car­bon nan­ofibers are grown using DC-PECVD at CMOS com­pat­ible tem­per­at­ures from cata­lyt­ic nan­o­particles, spin-coated from stable poly­mer-nan­o­particle col­loid­al sus­pen­sions. Two dif­fer­ent cata­lysts, Co and Cu, are invest­ig­ated by grow­ing car­bon nan­ofibers at tem­per­at­ures ran­ging from 390 °C to 550 °C, using sus­pen­sions with vari­ous con­cen­tra­tions of nan­o­particles. The length and mor­pho­logy of the grown nan­ofibers are examined using SEM and the elec­tric­al prop­er­ties are invest­ig­ated using elec­tro­chem­ic­al meas­ure­ments on samples arranged as super­ca­pa­cit­or devices. Ver­tic­ally aligned CNFs are suc­cess­fully grown from both types of cata­lyst. The Co-derived fibers are long and arranged in a dens­er car­pet-like struc­ture, while the Cu-derived fibers are short­er and in a spars­er form­a­tion of free-stand­ing indi­vidu­al fibers. All elec­tro­chem­ic­al meas­ure­ments show typ­ic­al super­ca­pa­cit­or beha­viour even at high scan rates of 200 mV/​s , with the fibers grown from Co show­ing great increase in capa­cit­ance over the bare chip ref­er­ence device, includ­ing the samples grown at 390 °C.