Abstract
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.