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

• Published in: ChemCatChem Vol. 9; no. 22; pp. 4295 - 4300
• Main Authors: Vineesh, Thazhe Veettil, Sekar, Archana, Rajappa, Sivamathini, Pal, Shubhadeep, Alwarappan, Subbiah, Narayanan, Tharangattu N
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 23.11.2017
• Subjects: Benchmarks; Catalysis; Catalysts; Cathodes; Cobalt oxides; doping; Electric potential; electrochemistry; Electrolysis; Electrolytic cells; Graphene; Hydrogen evolution reactions; membranes; Metal oxides; Nitrogen; Noble metals; Oxygen evolution reactions; Platinum; Stability; water splitting
• ISSN: 1867-3880; 1867-3899
• DOI: 10.1002/cctc.201701018

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 (320 mAcm−2 at an operating voltage of 1.9 V for Co3O4/NrGO, with 199 mA cm−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 (270 mA cm−2 at an operating voltage of 1.9 V with a stability tested for more than 9 h). This work opens up the possibilities of designing lightweight water‐electrolysis cells without the use of commercial benchmark precious‐metal catalysts. Water splitting made cheap: A precious‐metal/metal‐oxides‐free, efficient alkaline water‐electrolysis full cell is constructed employing Co3O4 nitrogen‐doped reduced graphene oxide (Co3O4/NrGO) composite sponge as the anode and nickel nitrogen‐doped reduced graphene oxide (NiNG) as the cathode catalysts system. It exhibits a current density of 270 mA cm−2 at 1.9 V.