Hierarchical Nitrogen‐Enriched Carbon from Rationally Designed Polyimide Precursor for Exceptional Acetone Adsorption

Abstract

AbstractThe adsorption capacity of porous adsorbent to volatile organic compounds (VOCs) is restricted by pore size distribution and surface functionalities. In this study, we report an effective N‐doped porous carbon synthesis strategy using rationally designed polyimide as precursor and subsequently copper chloride (CuCl2) mild activation. Specifically, by carefully changing the thiourea/urea ratio, polyimide precursors of different configurations can be designed and synthesized, which not only facilitates the transformation to a mesoporous structure, but also slightly enriches the surface heteroatoms. These unique properties result in a series of hierarchical porous carbon with high surface area (2045 m2/g), large mesopore volume (1.32 cm3/g) and rich nitrogen content (8.95 at %). Such carbon consequently shows exceptional static acetone adsorption performance of 768 mg/g (25 °C) and 799 mg/g (15 °C) and fast dynamic transfer rate. The abundant mesoporous structure provides the necessary diffusion channels to shorten the transmission distance and transmission resistance of acetone molecules, thereby contributing to this high acetone adsorption performance. Moreover, electrostatic potential (ESP) charge analysis shows that the doping of nitrogen atoms can significantly change the charge distribution on the sample surface, and enhance the affinity with acetone molecules through electrostatic interaction and Lewis acid‐base interaction