Microscopic understanding of physical and electrochemical processes at electrolyte/electrode interfaces is critical for applications ranging from batteries, fuel cells to electrocatalysis. However, probing such buried interfacial processes is experimentally challenging. Infrared spectroscopy is sensitive to molecule vibrational signatures, yet to approach the interface three stringent requirements have to be met: interface specificity, sub-monolayer molecular detection sensitivity, and electrochemically stable and infrared transparent electrodes. Here we show that transparent graphene gratings electrode provide an attractive platform for vibrational spectroscopy at the electrolyte/electrode interfaces: infrared diffraction from graphene gratings offers enhanced detection sensitivity and interface specificity. We demonstrate the vibrational spectroscopy of methylene group of adsorbed sub-monolayer cetrimonium bromide molecules and reveal a reversible field-induced electrochemical deposition of cetrimonium bromide on the electrode controlled by the bias voltage. Such vibrational spectroscopy with graphene gratings is promising for real time and in situ monitoring of different chemical species at the electrolyte/electrode interfaces.

中文翻译：

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电解质/电极与石墨烯光栅的振动光谱。

微观理解电解质/电极界面处的物理和电化学过程对于从电池，燃料电池到电催化的应用至关重要。然而，探测这种埋藏的界面过程在实验上具有挑战性。红外光谱对分子的振动信号很敏感，但要接近界面，必须满足三个严格的要求：界面特异性，亚单分子分子检测灵敏度以及电化学稳定的红外透明电极。在这里，我们显示透明的石墨烯光栅电极为电解质/电极界面的振动光谱提供了一个有吸引力的平台：石墨烯光栅的红外衍射提供了增强的检测灵敏度和界面特异性。我们展示了吸附的亚单层溴化十六烷基三溴甲烷分子的亚甲基的振动光谱，并揭示了可逆的电场诱导的溴化十六烷基三溴甲烷在偏置电压控制下的电化学沉积。具有石墨烯光栅的这种振动光谱法有望用于实时和原位监测电解质/电极界面处的不同化学物种。