High-temperature pyrolysis behavior and structural evolution mechanism of graphene oxide: A ReaxFF molecular dynamics simulation

• Microstructure evolution mechanism of graphene oxide deflagration phenomenon. • Functional group desorption process of GO pyrolysis at high temperature. • Hybridization statistics and graphitization degree analysis of C atoms in GO. • C-O bond length statistics and structural analysis in graphene oxide. • The release process and quantity statistics of gas molecular of GO pyrolysis. An in-depth understanding of the structural evolution of graphene oxide (GO) at high temperatures is of crucial importance for tuning the properties of GO and synthesizing graphene-related materials from GO, which still has many unknown structural changes at the atomic scale. In this work, the overall structural change process and the local structural evolution mechanism during the high-temperature pyrolysis of GO were investigated by the ReaxFF molecular dynamics simulation method. The detonation process of GO was explored for the first time at the atomic simulation level, and the detonation point of GO was found to be positively correlated with the C/O ratio, which is highly consistent with previous experimental results. The bonding pattern between C-O in GO was sorted out, and the desorption mechanism of functional groups during pyrolysis was explained in detail by analyzing the ratio of sp 2 and sp 3 hybridized C atoms. In addition, the effects of temperature, C/O ratio and functional group type on the small molecule pyrolysis products were also investigated. The present study provides strategies to tune GO structure by pyrolysis at high temperature.