NiCoP Nanopeapods Embedded in Carbon Nanotubes Arrays as Bifunctional Catalysts for Efficient Overall Water Splitting

Abstract The development of earth-abundant and durable electrocatalyts with high acivity are important to realize efficient overall water splitting. Herein, we report the design and fabriation of a bifunctional catalyst of NiCoP nanopeapods embedded in carbon nanotubes arrays (NiCoP nanopeapods/CNTs) for overall water splitting. The unique nanopeapods structure and synergistic effect between the bimetallic phosphides and carbon nanotubes make it be excellent bifunctional electroactivity and structural stability. Speicfically, the NiCoP nanopeapods/CNTs electrode requires an overpotential of 82 mV and 250 mV to reach a current density of 10 mA cm-2 in 1 M KOH medium for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively. Moreover, the NiCoP nanopeapods/CNTs are used as both cathode and anode for an alkaline electrolyzer, which only requirs a cell voltate of 1.558 V at 10 mA cm-2, which is superior to most of the non-precious metal catalyst for water splitting.