Conductive Carbon Nitride for Excellent Energy Storage

Conductive carbon nitride, as a hypothetical carbon material demonstrating high nitrogen doping, high electrical conductivity, and high surface area, has not been fabricated. A major challenge towards its fabrication is that high conductivity requires high temperature synthesis, but the high temperature eliminates nitrogen from carbon. Different from conventional methods, a facile preparation of conductive carbon nitride from novel thermal decomposition of nickel hydrogencyanamide in a confined space is reported. New developed nickel hydrogencyanamide is a unique precursor which provides self-grown fragments of center dot N=C=N center dot or N C=C N and conductive carbon (C-sp2) catalyst of Ni metal during the decomposition. The final product is a tubular structure of rich mesoporous and microporous few-layer carbon with extraordinarily high N doping level (approximate to 15 at%) and high extent of sp2 carbon (approximate to 65%) favoring a high conductivity (>2 S cm(-1)); the ultrahigh contents of nongraphitic nitrogen, redox active pyridinic N (9 at%), and pyrrolic N (5 at%), are stabilized by forming Ni. N bonds. The conductive carbon nitride harvests a large capacitance of 372 F g(-1) with >90% initial capacitance after 10 000 cycles as a supercapacitor electrode, far exceeding the activated carbon electrodes that have <250 F g(-1).