Development of three-dimensional iron-doped cobalt phosphides nanorod arrays coupled on nickel substrate for effective hydrogen and oxygen production

To reach practical generation of hydrogen energy from water, it is necessary to synthesize bifunctional effective and durable electrocatalyst towards hydrogen evolution and oxygen evolution reaction (HER and OER). However, the slow kinetics of HER and OER at the cathode and anode is the main bottleneck. Herein, a novel fabrication nanostructure of iron-doped cobalt phosphides nanorod arrays on a conducting nickel foam substrate (Fe-Co_xP_y NR/NF) is developed with uniform spreading of dopant, high catalytic activity area, rapid efficiency of interfacial charge transfer, and long-time operation by using a facile hydrothermal process and phosphidization. The results displayed that Fe-Co_xP_y NR/NF exhibited an effective overpotential of 98 mV towards HER and 290 mV towards OER at 10 mA cm⁻², which are much lower than those individual Co_xP_y NR and Fe-CoOH NR materials. In addition, the Fe-Co_xP_y NR/NF show significant stability in 1.0 M KOH, compared to commercial materials.