Electrocatalysts Based on Metal@carbon Core@shell Nanocomposites: An Overview

Developing low-cost, high-performance catalysts is of fundamental significance for electrochemical energy conversion and storage. In recent years, metal@carbon core@shell nanocomposites have emerged as a unique class of functional nanomaterials that show apparent electrocatalytic activity towards a range of reactions, such as hydrogen evolution reaction, oxygen evolution reaction, oxygen reduction reaction, and CO2 reduction reaction, that are important in water splitting, fuel cells and metal-air batteries. The activity is primarily attributed to interfacial charge transfer from the metal core to the carbon shell that manipulate the electronic interactions between the catalyst surface and reaction intermediates, and varies with the structures and morphologies of the metal core (elemental composition, core size, etc.) and carbon shell (doping, layer thickness, etc.). Further manipulation can be achieved by the incorporation of a third structural component. A perspective is also included highlighting the current gap between theoretical modeling and experimental results, and technical challenges for future research.