Efficient Metal-Free Electrocatalysts from N-Doped Carbon Nanomaterials: Mono-Doping and Co-Doping

N-doped carbon nanomaterials have rapidly grown as the most important metal-free catalysts in a wide range of chemical and electrochemical reactions. This current report summarizes the latest advances in N-doped carbon electrocatalysts prepared by N mono-doping and co-doping with other heteroatoms. The structure–performance relationship of these materials is subsequently rationalized and perspectives on developing more efficient and sustainable electrocatalysts from carbon nanomaterials are also suggested.