Arrayed CNx NT–RuO2 nanocomposites directly grown on Ti-buffered Si substrate for supercapacitor applications

Significant enhancement in supercapacitor performance has been achieved via a new RuO₂ nanocomposite materials prepared by direct ruthenium sputtering on arrayed multi-walled carbon nanotubes supported by Ti-buffered Si wafer. XPS, HRTEM and SAED analyses reveal that as-prepared nanoparticles have a crystalline Ru metal core with RuO₂ oxide coating. The nanocomposites convert to RuO₂–CN_x NTs with subsequent electrochemical cycling. At present, well-dispersed and strongly adhered RuO₂ NPs have been densely populated on CN_x NTs to obtain the overall specific capacitance (1380 F/g-RuO₂), charging–discharging rate (up to 600 mV/s) and operation stability (5000 cycles). Thus, RuO₂–CN_x NTs nanocomposites would make a promising candidate for use in next-generation high efficiency miniaturized supercapacitors directly fabricated on Si substrate.