Bimetallic Ni-Fe phosphide nanocomposites with a controlled architecture and composition enabling highly efficient electrochemical water oxidation

Developing cost-effective and earth-abundant noble-metal-free oxygen evolution reaction (OER) electrocatalysts with high activity and durability is highly desirable for future renewable energy systems. Herein, we develop a facile and controllable approach to engineer a series of structurally tiered bimetallic Ni-Fe phosphide nanocomposites with well-designed architectures and compositions through the topological conversion of the flowerlike precursor of Ni-Fe layered double hydroxides (LDHs). Remarkably, benefitting from their special physicochemical features and desirable synergistic effect, the resultant bimetallic phosphides can serve as a class of advanced high-performance electrocatalysts for water oxidation with an extremely low overpotential of 233 mV to deliver a current density of 10 mA cm(-2), a small Tafel slope of 42.5 mV dec(-1), and strong durability (30 h of continuous water electrolysis), favourably representing the state-of-the-art level. This work elucidates the promising electrocatalytic performance of multinary transition-metal phosphides with controlled structures and compositions derived from LDHs for the OER.