A practical-oriented NiFe-based water-oxidation catalyst enabled by ambient redox and hydrolysis co-precipitation strategy

Abstract Although NiFe-based (oxy)hydroxides have been recognized as the most promising anode materials for industrial water splitting, the existed synthetic methods are difficult to fabricate NiFe-based (oxy)hydroxides simultaneously fulfilling the requirements of low-cost and ambient synthetic process, high performance, and easier realization of large-scale production. In this work, a simple while effective strategy was proposed to fabricate well-aligned Ni-Fe hydroxide nanosheets array on Ni foam (NiFe-OH NS/NF) by the ambient spontaneous redox reaction between Ni foam and Fe3+and accompanied hydrolysis co-deposition of the generated Ni2+, Fe2+/Fe3+, and OH−. The tailored highly-oriented amorphous and nanoporous nanosheets structure as well as the strong electronic interaction between Ni and Fe species endow this NiFe-OH NS/NF with excellent OER activity that a large current density of 500 mA cm−2 could be well afforded at a low overpotential of 292 mV. Importantly, the manufacturing and raw-materials cost to synthesize the NiFe-OH NS/NF by this strategy is estimated to be just $0.0165 per cm2, much lower than those for other reported self-supported Fe-containing catalyst materials. Also, this ambient means not only could be applicable to the large-scale production of size-tunable NiFe-OH NS/NF with stable nanoarray structure, but also could be easily used for the synthesis of NiCo NS/NF and NiCoFe NS/NF for applications.