LAUSR

Abstract To make it commercially available for use in electricity production, hydrogen is required to be stored for roughly one to four decades. Through the application of the green energy technique, hydrogen used in fuel cells can be obtained from electrolysers. Platinum group metals (PGMs) are normally used to electrocatalyse the reactions, such as hydrogen and oxygen evolution reactions (HER and OER) and oxygen reduction reaction (ORR), which occur in fuel cells and electrolysers. This work reports the development and application of electrocatalysts with suitable properties using Co and Mo oxides with or without MoSe2 and in combination or not with graphene nanoribbons (GNRs), which are capable of supporting low amount of Pt and are highly efficient for OER and HER. Based on the results obtained, CoMoSe/GNR was found to be the best and most stable electrocatalyst for OER. The improvements observed in OER eletrocatalytic properties were attributed to the synergistic effects of binary metal ions, including Co2+, Co3+, Mo4+, and Mo6+ (transition metals intercalated across the nanostructures, with Co2+ and Mo4+ acting as active sites), as well as the interactions between the metals and ion support (geometric effects, charge transfer) and between the different oxides employed. PtCoMo was found to be the best and most stable electrocatalyst for HER. The improvements observed in HER properties were attributed to the presence of Pt0 and Pt2+metal/ions supported on CoMo structures — the strong interaction between Pt and Co/Mo oxides on PtCoMo nanocomposites interface produced electron-deficient Ptδ+ species — and the synergistic effects involving the Pt metal/ions and the binary metal ions, including Co2+, Co3+, Mo4+, and Mo6+ (transition metals intercalated across the nanostructures), in the reaction process. A significantly low amount of Pt (4.5 µgPt cm−2) was used for the construction of the PtCoMo/CP electrode.