Electrodeposition of porous MoO42--doped NiFe nanosheets for highly efficient electrocatalytic oxygen evolution reactions

The efficiency of water splitting is restricted by the slow kinetics of oxygen evolution reaction (OER) for large scale hydrogen production. Designing highly efficient, low-cost and long-lasting catalysts for OER is being actively pursued. In order to improve the catalytic activity of nickel-iron hydroxide (NiFe) for OER, MoO42− as a promoter is doped into NiFe. We reported a porous amorphous MoO42--doped nickel-iron hydroxide (NiFeMo) composite on nickel foam (NF) via a facile electrodeposition method. The as-prepared NiFeMo/NF electrode displays a highly efficient catalytic activity for OER in alkaline solution and delivers a current density of 20 mA cm−2 with an overpotential merely of 230 mV in 1.0 M KOH. The catalyst also exhibits extraordinary performance at high current densities and is comparable to the some Ni-based OER electrocatalysts reported to date. The high active surface areas, high surface wettability and the low charge-transfer resistance of NiFeMo/NF catalysts by a doping of MoO42−, together with effective mass transport offered by the hierarchical 3D macroporous structure, all contribute to the extraordinary synergistic OER performance.