The hierarchical nanowires array of iron phosphide integrated on a carbon fiber paper as an effective electrocatalyst for hydrogen generation

The development of an effective, non-precious electrocatalyst for the hydrogen evolution reaction (HER) is highly desirable for the commercial application of hydrogen as a clean and renewable energy and remains a substantial challenge. Herein, a hierarchical nanowires array (HNA) of iron phosphide (FeP) nanowires coated with iron phosphide nanorods grown on a carbon fiber paper (CFP) was constructed which exhibited remarkable catalytic activity in the HER. The overpotential required for the current density of 20 mA cm(-2) is as small as 45 and 221 mV in acidic and basic solution, respectively, corresponding to Tafel slopes of 53 and 134 mV dec(-1). The effective catalytic activity of the CFP-FeP HNA in the HER, together with its long-term stability and nearly 100% faradaic efficiency in water electrolysis, make the CFP-FeP HNA one of the best non-noble electrocatalysts described to date. The prominent catalytic activity of CFP-FeP HNA is correlated to the large number of active sites for the HER, and the fast electron transport from the CFP to the FeP nanorods mediated by FeP nanowires.