Nanoscale Icelike Water Layer on a Diamond Surface under Ambient Conditions

The chemical environment at interfaces plays an important role in controlling the structure, properties, and performance of low-dimensional materials. The water environment and adsorbates on solid surfaces are the most common interface environments that are prevalent in nonultrahigh vacuum conditions. Despite their ubiquitous presence, the structural and dynamic properties of these surface adsorbates are difficult to be directly characterized in situ at the atomic scale. Here, we report a dissection method leveraging shallow nitrogen-vacancy centers to quantitatively characterize nanoscale adsorbate layers on diamond surfaces with distinct structural and dynamical signatures. Our results reveal that under ambient conditions, a tightly bound organic adsorbate layer and an icelike interfacial water layer coexist on diamond surfaces. We further demonstrate that the rigidity of the interfacial water layer originates from its interaction with specific surface adsorption sites, such as the dangling bonds on the diamond surface. These findings establish new insights for investigating the structure and dynamics of low-dimensional adsorbates, as well as surface properties modulated by adsorbates under native conditions.