论文标题
观察结构演化和反应中间体处的栅极可调悬浮石墨烯/电解质界面
Observation of Structure Evolution and Reaction Intermediates at the Gate-tunable Suspended Graphene/Electrolyte Interface
论文作者
论文摘要
石墨烯是研究石墨电极界面处的显微镜结构和反应动力学的理想平台。但是，石墨烯易受各种外部因素的影响，例如底物，引起很多混乱和争议。因此，我们获得了CM大小的无底物单层石墨烯，该石墨烯悬挂在电解质表面上，带有栅极可调性。使用和频谱光谱法，我们观察到结构演化与石墨烯/水界面处的栅极电压。船尾层的结构在水电解窗口内是不变的，但是在打开电化学反应时会发生急剧变化。由于氢吸附而导致的氢进化反应发作，电极从疏水变成了亲水性。大型悬浮的原始石墨烯提供了一个新的平台，可以在石墨电极接口处揭示微观过程。
Graphene serves as an ideal platform to investigate the microscopic structure and reaction kinetics at the graphitic electrode interfaces. However, graphene is susceptible to various extrinsic factors, e.g. substrate, causing much confusion and controversy. Hereby we have obtained cm-sized substrate-free monolayer graphene suspended on electrolyte surface with gate tunability. Using sum-frequency spectroscopy, we have observed the structural evolution versus the gate voltage at the graphene/water interface. The Stern layer structure is invariant within the water electrolysis window, but undergoes drastic change when switching on the electrochemical reactions. The electrode is turned from hydrophobic to hydrophilic near the onset of hydrogen evolution reaction due to hydrogen adsorption. The large-size suspended pristine graphene offers a new platform to unravel the microscopic processes at the graphitic electrode interfaces.
