Guest-host modulation of multi-metallic (oxy) hydroxides for superb water oxidation

Multi-metallic (oxy) hydroxide materials are some of the most promising alternatives for superb water oxidation electrocatalysts. Herein, a series of graphene/NiFe (oxy) hydroxides were fabricated to investigate the role of the Fe/Ni ratio in regard to the resultant physical structures, decoration styles, and combined catalytic activities. With the Fe content increasing, a phase evolution from Fe doped Ni(OH)(2)/NiO(OH) to Ni doped FeO(OH) was demonstrated. The moderate guest-metal substitution into the host-oxyhydroxide framework (Fe into Ni or Ni into Fe) substantially enhanced the oxygen evolution activity with a decrease in both the Tafel slope and overpotential. In addition, the NiO(OH) and FeO(OH) frameworks exhibited distinct properties and performances for the oxygen evolution reaction due to the different metal-oxygen bond lengths and adsorption energies of the intermediates.