Bifunctional heterostructure NiCo-layered double hydroxide nanosheets/NiCoP nanotubes/Ni foam for overall water splitting

Development of highly active and stable bifunctional electrocatalysts for electrolysis of water is important for future renewable energy systems. Herein, the hierarchical heterostructure bifunctional electrocatalyst for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is fabricated by coupling NiCo-layered double hydroxide (NiCo-LDH) nanosheets with NiCoP nanotubes on Ni foam. The NiCo-layered double hydroxide (NiCo-LDH) nanosheets/NiCoP nanotubes/Ni foam exhibits excellent electrocatalytic performance in alkaline environment, which is determined by a low overpotential of 112 mV and 219 mV to reach 10 mA·cm−2 for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively. The as-prepared electrocatalyst as the anode and cathode only requires a cell voltage of 1.54 V to afford 10 mA·cm−2. The excellent electrocatalytic performance originates from the heterostructure and nanotubes structure, improving the intrinsic activity, providing a large specific surface area. This work provides a promising candidate for high-efficiency overall water splitting.