Two-dimensional (2D) materials are, in their monolayer limit, systems with only surface. Therefore, studying how they interact with the environment is of vital importance. Notably, we are interested in unraveling the oxidation mechanism at the atomic scale upon various conditions (e.g. low-pressure oxidation, high-pressure oxidation, plasma-induced oxidation, e-beam induce oxidation). The findings from this project can be beneficial for a better handling of 2D materials, and an improved control over the fabrication of related devices.