Mechanism of graphitization from fragmental carbon to graphite film

Using micromolecular glucose as a carbon source is an effective method for preparing high-performance graphite films. However, the microstructural evolution mechanism during this process remains unclear and warrants further investigation. In this study, we employed molecular dynamics simulations to reveal the graphitization mechanism of the carbon matrix. Our findings suggest two ways in microstructural evolves: First, the reconstruction of amorphous carbon fragments by sp³-sp² hybrid transformation leads to the gradual formation of the graphite layer. Second, the stratification caused by van der Waals forces. Furthermore, the structural parameter C_3σ of carbon clusters is defined to characterize the correlation between cluster structure and nucleation stability within the graphite layer. The stepwise growth of clusters and the selection preference for the adding ring type were quantitatively characterized. Ultimately, we introduced the molecular plane parameters and the span of deviation from plane to describe puckering observed in the graphite layer. It concluded that the different hybridization types and ring defects in the carbon matrix introduced by restructuring during graphitization are responsible for puckering. These results align well with experimental observations and provide fundamental insights into control mechanisms for graphitization while offering theoretical support for achieving high-performance graphite films.