Iron-induced lattice distortion generally boots the graphene-supported nickel phosphide nanoparticles catalysis for efficient overall water splitting

Rational design of high-efficient, low-cost and stable bifunctional electrocatalysts is necessary but challenging for water electrolysis. Transition metal phosphides (TMPs) with rich redox properties are considered to be the most promising substitutes for noble-metal materials but with aggregation and poor intrinsic electrical conductivity. Herein, we report an ultra-fast and controllable microwave strategy for synthesizing Fe-doped nickel phosphide on reduced graphene oxide (Fe-Ni 12 P 5 /rGO) as a highly active bifunctional electrocatalyst for both hydrogen and oxygen evolution reactions (HER and OER). It is noteworthy that Fe introduction can significantly cause the lattice distortion of Ni 12 P 5 and lead to the increase of electrocatalytic active sites and modulation of the electronic structure of each catalytic center. Benefiting from the highly active Fe-Ni 12 P 5 nanoparticles and two-dimensional graphene conductive network, the as-fabricated Fe-Ni 12 P 5 /rGO shows excellent electrocatalytic activity for HER and OER with good stability. In addition, an overall water splitting device with Fe-Ni 12 P 5 /rGO as both the cathode and anode electrocatalysts requires only an extremely low cell voltage of 1.57 V to reach 10 mA cm −2 , which is attractive among the latest research. This work provides a facile and effective approach for the design of high-performance transition metal-based electrocatalysts.