Mechanical behaviour and micro-mechanism of atomically precise edge graphene nanoribbons mechanical cutting guided by hydrogen atom adsorption

The preparation of graphene nanoribbons with atomically precise edges is a major challenge. In this paper, we proposed a mechanical cutting method for graphene nanoribbons guided by hydrogen atom adsorption and analysed the mechanical behaviour and microscopic cutting mechanism of graphene with hydrogen atom adsorption using reactive molecular dynamics simulations. The results showed that hydrogen atom adsorption weakened the mechanical properties and improved the cutting performance of graphene. Hydrogen atom adsorption showed a substantial guiding effect on graphene cutting, increasing the regular edge ratio from 12.21 % to 91.89 %, and graphene nanoribbons with atomically precise edges were prepared using this method. We determined that the cutting mechanism of graphene without hydrogen atom adsorption was a tensile-breaking mechanism. In contrast, graphene with hydrogen atom adsorption exhibited a shear-breaking mechanism. The cutting performance of the armchair-H graphene was lower than that of the zigzag-H graphene owing to the unique hexagonal distribution of carbon atoms. This study provides new insights into the cutting mechanism of graphene guided by hydrogen atom adsorption and establishes the method for preparing atomically precise edge graphene nanoribbons by mechanical cutting.