Oxygen‐Incorporated NiMoP Nanotube Arrays as Efficient Bifunctional Electrocatalysts For Urea‐Assisted Energy‐Saving Hydrogen Production in Alkaline Electrolyte

To couple hydrogen evolution reaction (HER) with urea oxidation reaction (UOR) is a promising approach to produce H2 with reduced energy consumption. However, the development of a low‐cost and high‐performance bifunctional electrocatalyst toward HER and UOR is still a challenge. In this work, oxygen‐incorporated nickel molybdenum phosphide nanotube arrays are synthesized on nickel foam (O‐NiMoP/NF) via electrodeposition accompanied with in‐situ template etching. Benefiting from the modulated electronic structure and the nanotube array architecture of O‐NiMoP, the self‐supporting O‐NiMoP/NF electrodes demonstrate highly efficient bifunctional catalytic activity toward HER and UOR. Particularly, in the HER and UOR (HER||UOR) coupled system for H2 production, a significantly reduced cell voltage of 1.55 V is obtained at the current density of 50 mA cm–2, which is about 300 mV lower than that of the conventional water electrolysis. Density functional theory calculations reveal that the remarkable HER and UOR activities originated from the Ni sites with the modulated electronic environment induced by Mo, P and O atoms, which facilitate the water dissociation during HER and balance the adsorption/desorption of the intermediates during UOR. The development of Ni‐based phosphides nanotube arrays as a bifunctional electrocatalyst in HER||OER system provides a new approach enabling energy‐saving H2 production. Oxygen‐incorporated nickel molybdenum phosphide nanotube arrays supported on nickel foam (O‐NiMoP/NF) for electrocatalytic urea oxidation reaction (UOR) and hydrogen evolution reaction (HER) are synthesized via electrodeposition accompanied with in situ template etching. Benefiting from the nanotube array architecture and the modulated electronic environment of O‐NiMoP, the O‐NiMoP/NF electrodes exhibit efficient bifunctional electrocatalytic activity in the HER||UOR coupled system for H2 production with a low voltage of 1.55 V at 50 mA cm−2.