化学状态及电场对石墨烯基材料纳米摩擦起电效应影响的研究

Nanoscale triboelectrification is crucial for the output performance and stability of graphene-based self-powered electronic devices. Chemical states and electric field are important factors affecting the nanoscale triboelectrification behavior. In this project, we will focus on the effects of chemical states and electric field on nanoscale triboelectrification characteristics of graphene based materials. Utilize PeakForce tapping mode / contact mode atomic force microscopy (AFM), and a new scanning polarization force microscopy as well as Kelvin probe force microscopy to control the contact- and sliding-mode processes of tip-sample precisely and quantitatively characterize the surface/interface charges in situ at nanoscale. The regular changes in chemical state of graphene can be achieved through modulating the reduction degree of graphene oxide and combining with pristine graphene. The transverse and vertical electric field will be generated by constructing nanoscale isolated charges and applying AFM tip bias, respectively. We aim to quantitatively study the nanoscale triboelectrification characteristics of graphene based materials with varied chemical states in electric field. This study will be helpful to reveal the influence mechanism of chemical states and electric field on triboelectrification of graphene-based materials, and provide new ideas to enhance or nullify the triboelectrification for high performance as well as the operation stability of devices. It’s a cutting-edge research topic in the field of nano-energy and tribotronics.

纳米尺度摩擦起电效应是决定石墨烯基自驱动电子器件输出性能和稳定性的关键要素。化学状态和电场是影响纳米摩擦起电行为的重要因素。本项目将致力于化学状态和电场对石墨烯基材料纳米摩擦起电效应影响与调控的研究，拟采用基于扫描探针显微技术的峰值力轻敲模式加接触模式原子力显微镜（AFM）以及新型扫描极化力显微镜加经典开尔文探针力显微镜，实现针尖-样品摩擦运动过程的定量操控与表/界面摩擦电荷的纳米尺度原位定量表征，通过调节氧化石墨烯还原程度结合原始石墨烯实现石墨烯化学状态的规律性变化，通过构建纳米电荷产生横向电场、AFM针尖施加偏压产生纵向电场，系统定量研究化学状态及电场对石墨烯基材料纳米摩擦起电性质的影响。该研究将有助于揭示化学状态和电场对石墨烯基材料纳米摩擦起电行为调控的机理，为摩擦起电过程的有效强化或防静电设计给出指导，以提高器件的输出性能和运行稳定性，是纳米能源及摩擦电子学领域的前沿研究课题。

纳米尺度摩擦起电效应是决定石墨烯基自驱动电子器件输出性能和稳定性的关键要素。化学状态和电场是影响纳米摩擦起电行为的重要因素。本项目通过调节氧化石墨烯还原程度结合原始石墨烯，实现了石墨烯基材料化学状态的纳米尺度调控与规律性变化；研究了化学状态对纳米摩擦起电效应的影响，发现在氧化石墨烯片层上，摩擦电荷只分布在摩擦区域，而在还原态氧化石墨烯上，摩擦电荷在整个片层上是离域分布的；阐明了表面粗糙度、接触力和摩擦方式等摩擦因素对摩擦起电过程的影响及机制，建立了通过调节纳米尺度氧化程度改变石墨烯化学状态进而调控其摩擦起电效应的方法；揭示了摩擦电势与初始电势之间存在线性依赖相关，并研究了样品初始电势随时间的演化、初始电势对样品表面隧穿摩擦起电效应的影响，同时提出了导电探针和样品间摩擦起电过程的电荷转移机制；对电场调控摩擦起电行为进行了定量研究，实现了石墨烯基材料摩擦起电效应强度和极性的调节，通过控制摩擦起电现象构造了纳米电荷图案。这些研究结果帮助我们理解化学状态和电场如何对石墨烯基材料纳米摩擦起电行为进行调控，可以为摩擦起电过程的有效强化或防静电设计给出指导，以提高器件的输出性能和运行稳定性，在纳米能源及摩擦电子学领域具有重要的学术价值。