Self-supported bimetallic phosphides with artificial heterointerfaces for enhanced electrochemical water splitting

Rational design and exploitation of efficient and inexpensive catalysts for water electrolysis are highly desired, yet very challenging. Herein, for the first time, we report a nanostructured catalyst of nickel phosphides-ruthenium phosphides self-supported on nickel foam (Ni2P-Ru2P/NF) through an in situ growth-phosphorization process. As expected, by virtue of prominent intrinsic activity, rich electrochemically active sites, and high electronic conductivity, the resultant Ni2P-Ru2P/NF exhibits enhanced electrocatalytic behavior for the oxygen evolution reaction and hydrogen evolution reaction, which delivers low overpotentials of 160 and 101 mV at 10 mA cm2 in alkaline media, respectively. Remarkably, the Ni2P-Ru2P/NF can dramatically accelerate full water splitting with an ultralow cell voltage of 1.45 V at 10 mA cm−2, which far exceeds the benchmark Pt-C/NF//RuO2/NF (1.64 V) and ranks among the best electrocatalysts previously reported.