Stability of fullerenes under hydrothermal conditions

Abstract

Stability of fullerenes C60 under hydrothermal conditions (200-800°C, 100 MPa, 20 min-168 h) has been investigated. The reaction products have been characterized by Raman spectroscopy and x-ray diffraction. The fullerenes were stable up to 500°C, but they decomposed immediately at 800°C into amorphous carbon. In the transition region between 600 and 750°C, longer times and higher temperatures of the hydrothermal treatment favored decomposition of C60 with the formation of amorphous carbon. Addition of nickel to the C60-H2O system neither suppressed hydrothermal decomposition of C60 nor induced formation of other phases, except of the amorphous carbon.