Identify the Removable Substructure in Carbon Activation

• Published in: Chemistry of materials 2017-09, Vol.29 (17), p.7288-7295
• Main Authors: Xing, Zhenyu, Qi, Yitong, Tian, Ziqi, Xu, Jing, Yuan, Yifei, Bommier, Clement, Lu, Jun, Tong, Wei, Jiang, De-en, Ji, Xiulei
• Format: Article
• Language: English
• ISSN: 0897-4756; 1520-5002
• DOI: 10.1021/acs.chemmater.7b01937

Activated carbon plays a pivotal role in achieving critical functions, such as separation, catalysis, and energy storage. A remaining question of carbon activation is which substructures in amorphous carbon are preferentially removed during activation. Herein, we report the first structure–activation correlation elucidated on the basis of unprecedented comprehensive characterization on carbon activation. We discover that activation under CO2 preferentially removes graphenic layers that are more defective. Therefore, the resulting activated carbon contains thinned turbostratic nanodomains that are of a higher local graphenic order. The mechanistic insights explain why more defective soft carbon is “burned” under CO2 at a much faster rate than hard carbon. The mechanism leads to an activation-based design principle of mesoporous carbon. Guided by this principle, a bimodal micromesoporous carbon is prepared simply by CO2 activation. Our findings may cause a paradigm shift for the rational design of nanoporous carbon.