Electrodeposited Iron Phosphide Film As an Efficient Electrocatalyst for Hydrogen Evolution Reaction

Abstract

To scale up hydrogen evolution reaction from electrochemical water splitting, a remaining challenge is to replace precious Pt catalysts with cost-effective catalysts. Recently, iron phosphide (FeP) was discovered to be a good substitute for platinum because of the extreme abundance and low cost of iron. Unfortunately, the synthesis of FeP typically requires harsh conditions, which usually cause the decomposition of phosphide precursors and the generation of highly corrosive and flammable phosphorus. Herein, we developed a straightforward and cost-effective method to electrodeposit FeP film on copper electrode at room temperature. The prepared FeP film only requires an overpotential of 66 mV in 0.5 M H 2 SO 4, 131 mV in 1.0 M PBS and 110 mV in 1.0 M KOH, to achieve the current density of 10 mA/cm 2 , as well as Tafel slope of 55 mV/dec, 108 mV/dec, 60 mV/dec, respectively. In addition, the FeP shows excellent stability over 24 hours and gives about 100% Faradaic efficiency.