利用克氏探針表面電位顯微術檢測大氣下氧化石墨烯表面水分子的吸附

Detection of Water Absorption on Graphene Oxide Surface by Kelvin Probe Force Microscopy under Ambient Conditions

在大氣環境下，水分子在材料表面的吸附會改變其物理或化學特性，並且對各種科學與工程的領域都有重要的影響。克氏探針表面電位顯微術本身具有原子力顯微術在奈米尺度取得高解析度影像的能力，加上對材料功函數量測的功能，具有用來檢測大氣環境下水分子在材料表面吸附程度的潛力。在本文中，我們將介紹克氏探針表面電位顯微術的基本原理。我們並將以氧化石墨烯為例，簡介在大氣環境下，如何利用克氏探針表面電位顯微術，以及實驗過程中環境溼度的變化，來探討水分子的吸附對氧化石墨烯功函數的影響。對奈米材料的研究而言，克氏探針表面電位顯微術會是個用來探討水分子如何吸附到材料表面，與如何影響材料性質的有利工具。

The absorption of water molecules on surfaces can change the physiochemical properties of the materials, which play significant roles in various fields of science and engineering. Kelvin probe force microscopy (KPFM), a technique that can simultaneously provide topography imaging and work function mapping of a material surface with high spatial resolution at the nanoscale, can potentially be used to detect the absorption of water molecules on a surface under ambient conditions. Here, we will introduce the fundamentals of Kelvin probe force microscopy. Using graphene oxide (GO) as an example, we will also discuss how we can employ KPFM to investigate the impact of water absorption on the work function of GO under various environmental humidity. Our results demonstrate that KPFM can be an effective tool to investigate water absorption on surfaces and how the absorbed water molecules impact the properties of nanomaterials.