In-situ construction of pomegranate-like nickel-vanadium nitride for hydrogen production through urea-assisted water-splitting

To accelerate the promotion of hydrogen energy utilization, the research of efficient and stable catalysts has been the priority, and the combination of multifunctional catalytic performance for hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and urea oxidation reaction (UOR) is needed. Transition metal nitrides (TMNs) is considered as an inexpensive alternative to noble metal-based catalysts. However, NH3 is mostly used in TMNs synthesis method, which is contrary to the original intention of environmental protection. Herein, nickel-vanadium nitride (VN) with pomegranate nanostructure grown on Ni foam (NF) is obtained by hydro thermal and following environmental-friendly urea nitridation approach (Ni/VN/NF). Remarkably, Ni/VN/NF exhibits excellent electrocatalytic performances for HER, OER and UOR. Remarkably, the electrolyzer can be driven to produce hydrogen through intermittent energy sources, such as wind, solar, and thermal energy, proving its potential applications on storing the renewable energies. This work provides a strategy for the development of high-performance TMNs for urea-assisted water-splitting.