A high-performance electrocatalyst composed of nickel clusters encapsulated with a carbon network on TiN nanaowire arrays for the oxygen evolution reaction

Metal cluster catalysts have aroused much interest in the field of electrocatalysis due to high degree of materials utilization and strong substrate interaction, but negative effects such as materials aggregation must be minimized. In this work, rhizobia-like Ni nano-clusters encapsulated with a carbon network are anchored on porous TiN nanowire arrays prepared on carbon cloth (CC) to form a high-performance electrocatalyst for the oxygen evolution reaction (OER) in water splitting. The Ni nano-clusters with a small size and strong interaction with the TiN substrate provide active sites galore to facilitate OER. Furthermore, the skeleton made of porous TiN nanowires on CC provides high electrical conductivity to accelerate charge transport as well as a rough surface to accommodate the Ni nano-clusters. The interaction between the metallic Ni nano-clusters and TiN substrate are demonstrated to promote the activity in OER based on theoretical calculation. This novel electrocatalyst which exhibits superior OER activity and stability in an alkaline electrolyte has large potential in energy conversion and related applications.