Atomically thin two-dimensional (2D) materials are excellent candidates for utilization as a solid lubricant or additive at all length scales from macro-scale mechanical devices to micro/nano-electromechanical systems (MEMS/NEMS). In such applications, wear resistance of ultrathin 2D materials is critical for sustained lubrication performance. Here, we investigated the wear of fluorinated graphene (FG) nanosheets deposited on silicon surfaces using atomic force microscopy (AFM) and discovered that the wear resistance of FG improves as the FG thickness decreases from 4.2 to 0.8 nm (corresponding to seven layers to single layer) and the surface energy of the substrate underneath the FG nanosheets increases. On the basis of density function theory (DFT) calculations, the negative correlation of wear resistance to FG thickness and the positive correlation to substrate surface energy could be explained with the degree of interfacial charge transfer between FG and substrate which affects the strength of FG adhesion to the substrate.

中文翻译：

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氟化石墨烯的厚度与磨损成反比关系：“越薄越好”

原子级薄的二维 (2D) 材料是从宏观机械设备到微/纳米机电系统 (MEMS/NEMS) 的所有长度尺度上用作固体润滑剂或添加剂的绝佳候选材料。在此类应用中，超薄二维材料的耐磨性对于持续润滑性能至关重要。在这里，我们使用原子力显微镜 (AFM) 研究了沉积在硅表面上的氟化石墨烯 (FG) 纳米片的磨损，发现随着 FG 厚度从 4.2 nm 减小到 0.8 nm（对应于七层到单层），FG 的耐磨性会提高。层）并且FG纳米片下方的基板的表面能增加。在密度函数理论 (DFT) 计算的基础上，