Multistep Transformation from Amorphous and Nonporous Fullerenols to Highly Crystalline Microporous Materials

The structural and morphological properties of fullerenols upon exposure to heat treatment have yet to be understood. Herein, the temperature-driven structural and morphological evolutions of fullerenols C-60(OH) and C-70(OH) were investigated. In situ spectroscopic techniques, such as variable-temperature X-ray diffraction and coupled thermogravimetric Fourier-transform infrared analysis, were used to elucidate the structural transformation mechanism of fullerenols. Both fullerenols underwent four-step structural transformation upon heating and cooling, including amorphous-to-crystalline transition, thermal expansion, structural compression, and new crystal formation. Compared to the initially nonporous amorphous fullerenol, the crystalline product exhibited microporosity with a surface area of 114 m(2) g(-1) and demonstrated CO2 sorption capability. These findings show the potential of fullerene derivatives as adsorbents.

Automated summary

This study investigates the structural and morphological evolutions of fullerenols under temperature changes using in situ spectroscopic techniques. The results reveal that fullerenols undergo four-step structural transformations, leading to the formation of crystalline products with microporosity and CO2 sorption capability.