The carbonization of aromatic molecules with three-dimensional structures affords carbon materials with controlled pore sizes at the \xc5ngstrom-level

Tomoki Ogoshi,Rui Tang,Takahiro Kakuta,Katsuto Onishi,Tada-Aki Yamagishi,Yuma Sakatsume,Kazuma Takahashi,Yuta Nishina,Benoît D L Campéon,Hirotomo Nishihara

doi:10.1038/s42004-021-00515-0

Abstract

Carbon materials with controlled pore sizes at the nanometer level have been obtained by template methods, chemical vapor desorption, and extraction of metals from carbides. However, to produce porous carbons with controlled pore sizes at the Ångstrom-level, syntheses that are simple, versatile, and reproducible are desired. Here, we report a synthetic method to prepare porous carbon materials with pore sizes that can be precisely controlled at the Ångstrom-level. Heating first induces thermal polymerization of selected three-dimensional aromatic molecules as the carbon sources, further heating results in extremely high carbonization yields (>86%). The porous carbon obtained from a tetrabiphenylmethane structure has a larger pore size (4.40 Å) than those from a spirobifluorene (4.07 Å) or a tetraphenylmethane precursor (4.05 Å). The porous carbon obtained from tetraphenylmethane is applied as an anode material for sodium-ion battery.

Highlights

Carbon materials with controlled pore sizes at the nanometer level have been obtained by template methods, chemical vapor desorption, and extraction of metals from carbides
Thermal polymerization of the ethynyl groups resulted in the formation of cross-linked polymers, which contributed to the high yield of production of carbon materials C1 and C2 by carbonization
We were able to prepare carbon materials with pore sizes controlled at the Ångstrom level by carbonization of the designed carbon sources, which were 3D aromatic molecules with ethynyl groups

Summary

Introduction

Carbon materials with controlled pore sizes at the nanometer level have been obtained by template methods, chemical vapor desorption, and extraction of metals from carbides. We report a synthetic method to prepare porous carbon materials with pore sizes that can be precisely controlled at the Ångstrom-level. Carbon materials with controlled pore sizes at the nanometer level are obtained as negative replicas of the inorganic templates. These methods depend on a craftsmanship process, which is based on a number of empirical parameters This craftsmanship process has been the greatest hinderance to obtain porous carbons with controlled pores at the Ångstrom level using the procedures reported by different research groups. By molecular design of the carbon sources, we were able to demonstrate the chemically sophisticated pore-size control of porous carbons at the Ångstrom level. The porous carbon C1 derived from 1 shows high conductivity and works as an anode electrode material for lithium- and sodium-ion batteries

Methods

Results

Conclusion