Rational design of ultrahigh porosity Co foam supported flower-like FeNiP-LDH electrocatalysts towards hydrogen evolution reaction

Abstract The development of high-efficiency, stable and low-cost electrocatalysts is a matter of cardinal significance for large-scale electrolytic hydrogen production from water. In this study, we report a hierarchical electrocatalyst of flower-like FeNiP-LDH (FeNiP on layered double hydroxide) loaded on ultrahigh porosity Co foam. The structure/component superiorities and hydrogen evolution reaction (HER) performance of this electrode were examined in detail. In alkaline solution, the resulting FeNiP-LDH/CF yields a current density of 10 mA/cm2 at an overpotential of -39 mV, which is superior than most documented transition metal phosphides electrocatalysts and even Pt catalyst (~ -53 mV). In particular, this electrode with an undamaged microstructure can maintain its HER activity over 16 h at high current density of 500-600 mA/cm2. Such remarkable HER performance originates from the satisfactory porous nature of Co foam as well as the special surface structure and electronic properties of phosphide/hydroxide. This work not only offers a viable modular approach for the synthesis of high-performance HER electrocatalysts, but also allows an in-depth understanding of structure-activity relationships of multistage 3D materials for energy and catalysis application.