Fig. 1From: Selective synthesis of pure cobalt disulfide on reduced graphene oxide sheets and its high electrocatalytic activity for hydrogen evolution reaction a XRD patterns of CoS2/rGO. Cobalt sulfides without GO (black) and CoS2/rGO with 1 mg/mL GO (red) and 2.3 mg/mL GO (blue) compared with standard patterns for CoS2 (navy lines), CoS (pink lines), Co3S4 (green lines), and Co3O4 (violet lines). b Raman spectrum of CoS2/rGO with 2.3 mg/mL GOBack to article page