A Self‐Sacrificing Dual‐Template Strategy to Heteroatom‐Enriched Porous Carbon Nanosheets with High Pyridinic‐N and Pyrrolic‐N Content for Oxygen Reduction Reaction and Sodium Storage

Controllable synthesis of 2D carbon nanosheets with high heteroatom‐doping level, large specific surface area, and hierarchically pore structure is difficult and desired. In this work, a novel and simple self‐sacrificing in situ formed dual‐template strategy is first developed to synthesize N/S codoped hierarchically porous carbon nanosheets. The in‐situ formed g ‐C 3 N 4 and amorphous ZnO act as self‐sacrificing templates on account of their thermal decomposition and evaporation at higher temperature. The N/S codoped hierarchically porous carbon nanosheets simultaneously possess high heteroatom‐doping level (N: 10.51 wt%; S: 1.71 wt%), large specific surface area (904.63 m 2 g −1 ), and abundant hierarchically porous structure. Particularly, this material possesses a high content of pyridinic‐N and pyrrolic‐N configuration (65.66%). These unique structure advantages of N/S codoped hierarchically porous carbon nanosheets contribute to high oxygen reduction electrocatalytic activity in both basic and acidic environments. Additionally, as the anode material for sodium‐ion batteries, the material also displays a high reversible capacity of 270.1 mAh g −1 at a current density of 100 mA g −1 and high stability (160.1 mAh g −1 after 2000 cycles at 1000 mA g −1 with a capacity retention of 82.3%). These results indicate a great potential of the material in energy conversion and storage applications.