One-step synthesis of a cobalt sulfide/reduced graphene oxide composite used as an electrode material for supercapacitors

A simple, one-step approach has been developed to prepare a composite of cobalt sulfide/reduced graphene oxide (CoS/rGO) by using sodium thiosulfate as a sulfur source. The reduction of GO and the growth of CoS occurred simultaneously, forming a hybrid structure with CoS anchoring on the rGO surface. The prepared CoS/rGO composite was applied as an electrode material and found to exhibit a high specific capacitance and rate capability, such as 550 F g(-1) and 400 F g(-1) at a current density of 1 A g(-1) and 40 A g(-1) respectively as well as excellent cyclic stability for 5000 cycles of charge-discharge. The CoS/rGO composite could be a promising electrode material for a high performance supercapacitor.