Non-Precious Metal/Metal Oxides and Nitrogen-Doped Reduced Graphene Oxide based Alkaline Water-Electrolysis Cell

The development of strategies for water-electrolysis half-cell-reaction catalysts without the use of precious metals/metal oxides and the synergistic compilation of catalysts for the full-cell fabrication are receiving tremendous scientific attention. Here, alkaline water-electrolysis full cells are developed with novel spongy catalysts for both anode and cathode reactions, such as Co3O4 nitrogen-doped reduced graphene oxide (Co3O4/NrGO) composite sponge for oxygen evolution reaction (OER) and nickel nitrogen-doped reduced graphene oxide (NiNrGO) for hydrogen evolution reaction (HER). The performance of the developed OER catalyst, Co3O4/NrGO, is compared with that of the commercial one (IrO2) in alkaline medium with a common benchmark cathode catalyst (Pt) and an augmented full-cell performance is shown from this novel combination (320mAcm(-2) at an operating voltage of 1.9V for Co3O4/NrGO, with 199mAcm(-2) for IrO2). A water-electrolysis full cell is developed without the use of HER catalyst Pt, but rather using a porous spongy catalyst, NiNrGO, having a low operating potential with a high stability (270mAcm(-2) at an operating voltage of 1.9V with a stability tested for more than 9h). This work opens up the possibilities of designing lightweight water-electrolysis cells without the use of commercial benchmark precious-metal catalysts.