Fig. 2From: Selective synthesis of pure cobalt disulfide on reduced graphene oxide sheets and its high electrocatalytic activity for hydrogen evolution reactionX-ray photoelectron spectra of the a Co 2p and b S 2p regions for CoS2 without GO (black) and for CoS2/rGO with 1 mg/mL GO (red) and 2.3 mg/mL GO (blue)Back to article page