热解-模板法制备石墨烯的分子动力学模拟探究

提出一种以废弃塑料热解产物为碳源，以石墨微片为模板，通过石墨微片的生长来制备石墨烯的设想。为了探索该设想的可行性和反应机理，以聚乙烯为例，采用反应分子动力学模拟方法从原子尺度对热解-模板法制备石墨烯的过程进行了研究。结果表明，在一定的温度条件下，聚乙烯分解产生具有高反应活性的乙烯基自由基和甲基自由基，这些自由基在降温过程中会接枝到石墨微片的边缘从而生长石墨烯。这说明以废弃塑料为碳源，加热分解后在石墨微片上生长石墨烯的设想具有可行性。分析了加热时间、冷却时间等条件对石墨烯生长过程的影响，可为实验制备石墨烯提供理论指导和参考。

Reactive molecular dynamics simulation of graphene preparation by the pyrolysis-template method

The preparation of graphene is currently a hot topic. This work investigates the possibility of preparing graphene by growth on the edge of templating graphite nanosheets using the intermediate products of the pyrolysis of waste plastic as precursors. The practicability of this concept and the mechanism of the reactions were investigated on an atomistic scale by carrying out reactive molecular dynamics simulations with polyethylene as an example of the plastic. The results reveal that the pyrolysis of polyethylene produces intermediate vinyl radicals and methyl radicals, which are highly reactive and are able to attach to the edge of the templating graphite nanosheets to promote the growth of graphene. This suggests that the proposed synthesis route is practical. The influence of varying the heating and cooling times on the growth of graphene was also analyzed. This work can provide useful guidelines for the experimental preparation of graphene.