Stacked Porous Iron-Doped Nickel Cobalt Phosphide Nanoparticle: An Efficient and Stable Water Splitting Electrocatalyst

Exploration of proficient electrocatalyst from earth-abundant nonprecious metals in lieu of noble metal-based catalysts to obtain clean hydrogen energy through large-scale electrochemical water splitting is still an ongoing challenge. Herein, iron-doped nickel cobalt phosphide nanoplate arrays grown on a carbon cloth (NiCoFe_xP/CC) are fabricated using a simple hydrothermal route, followed by phosphorization. The electrochemical analysis demonstrates that the NiCoFe_xP/CC electrode possesses high electrocatalytic activity for water splitting in alkaline medium. Benefits from the synergistic effect between the metal centers, two-dimensional porous nanoplates, and unique three-dimensional electrode configuration of NiCoFe_xP/CC provide small overpotentials of 39 at 10 mA cm^-2 and 275 mV at 50 mA cm^-2 to drive the hydrogen evolution reaction and oxygen evolution reaction, respectively. Furthermore, the assembled two-electrode (NiCoFe_xP/CC∥NiCoFe_xP/CC) alkaline water electrolyzer can achieve 10 mA cm^-2 current density at 1.51 V. Remarkably, it can maintain stable electrolysis over 150 h. The excellent activity and stability of this catalyst is proved to be a economical substitute of commercial noble metal-based catalysts in technologies relevant to renewable energy.