Nitrogen-doped carbon was derived from sorghum press cake following hydrothermal treatment. (SBET being 2668 m2 /g). Hydrothermal synthesis with thiourea was used to prepare NC_CoS and NC_NiS composites. SEM, N_2 adsorption and Raman spectroscopy revealed that Co forms a crystalline sulfide phase which is spread uniformly on the carbon network, whereas Ni yields an amorphous or highly dispersed sulfide. Electrochemical tests in 1 M of KOH showed that NC_CoS has a specific capacitance of 115 F/g at 1.3 A/g and retains 72% after 3500 cycles.
