N-doped bimetallic NiFeP nanocubic clusters derived from Prussian blue analogues as a high-efficiency and durable water splitting electrocatalyst

The design and preparation of high-efficiency and durable non-precious metal electrocatalysts are critical to the realization of large-scale water splitting. In this work, nano cubic clusters of Ni and Fe bimetallic phosphides (NiFeP@NC/NF) grown on NF substrates were synthesized through a simple secondary hydrothermal reaction and low-temperature phosphating. By exploring the phosphating temperature, the optimized NiFeP@NC/NF material shows excellent oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) properties in 1.0 M KOH electrolyte. It has a small initial overpotential of 286 and 242 mV and low Tafel slope of 69 and 126 mV dec −1 at current density of 20 mA cm −2 , which is attributed to the synergistic effect of NC@ NiFeP nanocubic clusters and NF framework, NiFeP@NC nanocubic clusters not only provide more active specific surface area but also the interlaced structure is more stable. The introduction of miscellaneous elements can accelerate the mass transfer in the reaction. The results show that NiFeP@NC/NF is an excellent dual-function electrocatalyst for water splitting and a promising candidate for electrocatalytic water splitting.