Nitrogen-Plasma-Activated Hierarchical Nickel Nitride Nanocorals for Energy Applications

Developing transition metal nitrides with unique nanomorphology is important for many energy storage and conversion processes. Here, a facile and novel one-step approach of growing 3D hierarchical nickel nitride (hNi₃ N) on Ni foam via nitrogen plasma is reported. Different from most conventional chemical synthesis, the hNi₃ N is obtained in much shorter growth duration (≤15 min) without any hazardous or reactive sources and oxide precursors at a moderate reaction zone temperature of ≤450 °C. Among possible multifunctionalities of the obtained nanocoral hNi₃ N, herein the performance in reversible lithium ion storage and electrocatalytic oxygen evolution reaction (OER) is demonstrated. The as-obtained hNi₃ N delivers a considerable cycling performance and rate stability as a lithium ion battery anode, and its property can be further enhanced by coating the hNi₃ N surface with graphene quantum dots. The hNi₃ N also serves as an active OER catalyst with high activity and stability. Additionally, on the basis of controlled growth under different nitrogen plasma treatment time, the formation mechanism of the nanocoralline hNi₃ N is outlined for further extension to other materials. The results on time- and energy-efficient nitrogen-plasma-based preparation of hNi₃ N pave the way for the development of high-performance metal nitride electrodes for energy storage and conversion.