Directed synthesis of carbon nanotube arrays based on layered double hydroxides toward highly-efficient bifunctional oxygen electrocatalysis

A free-standing three dimensional nitrogen-doped carbon nanotube (3D NCNT) array has been successfully fabricated via a directed growth approach, which can act as high-performance bifunctional oxygen electrocatalyst for ORR and OER. By using this self-supporting electrode material as air-cathode, a flexible, rechargeable all-solid-state Zn-air battery was assembled, which display desirable operational performances for energy storage and conversion.219