The investigation of solid−liquid interfaces is pivotal for understanding processes like wetting, corrosion, and mineral dissolution and growth. The graphite−water interface constitutes a prime example for studying the water structure at a seemingly hydrophobic surface. Surprisingly, in a large number of atomic force microscopy (AFM) experiments, well-ordered stripes have been observed at the graphite−water interface. Although many groups have reported on the observation of stripes at this interface, fundamental properties and, in particular, the origin of the stripes are still under debate. Proposed origins include contamination, interplanar stacking of graphene layers, formation of methanol−water nanostructures, and adsorption of nitrogen molecules. Especially, the latter interpretation has received considerable attention because of its potential impact on explaining the long-range nature of the hydrophobic interaction. In this study, we demonstrate that these stripes readily form when using standard plastic syringes to insert the water into the AFM instrument. In contrast, when clean glass syringes are used instead, no such stripes form even though nitrogen was present. We, therefore, conclude that contaminations from the plastic syringe rather than nitrogen constitute the origin of the stripes we observe. We provide high-resolution AFM data that reveal detailed structural insights into the arrangement of the stripes. The rich variability of our data suggests that the stripes might be composed of several different chemical species. Still, we cannot rule out that the stripes observed in the literature might originate from other sources; our study offers a rather straightforward explanation for the origin of the stripes. In the view of these results, we propose to carefully reconsider former assignments.

years 1999 to 2002, several tons of AgI were annually introduced into the atmosphere worldwide for weather modifications such as hail suppression, precipitation enhancement, or drought operation. [8][9][10] Already in 1947, Vonnegut has identified AgI as an excellent ice nucleating agent by searching for crystals with lattice constants that resemble the lattice constant of ice as closely as possible. [11] Indeed, AgI nucleates ice at around -4 °C. [4,11] The importance of small lattice mismatches between the AgI surface and ice has been investigated by Evans. [12] He has studied ice nucleation in the presence of AgI particles at pressures up to 3000 bar, allowing the nucleation of ice I and ice III. In these experiments, it has been observed that the ice phase with the better lattice match nucleates preferentially. From these results, it has been concluded that lattice match is an important factor in the ability to nucleate ice.Heterogeneous ice nucleation using AgI particles has been studied in different nucleation modes (immersion, deposition, contact, and condensation freezing). [4] It is known that the ice nucleation ability of AgI is reduced by photolytic decomposition of the crystal. AgI decomposes mainly when exposed to ultraviolet light (λ < 440 nm). [13,14] When irradiated with light with wavelengths above 440 nm, the photolysis of AgI occurs to a lesser extent. [13] The photolysis also depends on the amount of adsorbed water on the AgI surface. When water is adsorbed on the surface, the photolysis is reduced. This is seen from the fact that the ice nucleation effectiveness is maintained for longer time when water is present. [15] The hydrogen bonding structure of adsorbed water molecules on AgI powder has been investigated with X-ray photoelectron spectroscopy and near edge X-ray adsorption fine structure spectroscopy. It has been found that the water molecules adsorbed on AgI indeed exhibit an ice-like hydrogen bonding structure. [16] Two polymorphs of AgI are stable at temperatures under 147 °C and at ambient pressures: βand γ-AgI. [17,18] While the metastable γ-AgI crystallizes in the zincblende structure, the thermodynamically stable β-AgI adopts the wurtzite crystal structure.Figure 1a shows a side view of the ( 0001) surface of β-AgI. The silver and purple spheres represent the silver cations and the iodide anions, respectively. The structure of β-AgI consists Silver iodide (AgI) particles are known for their outstanding ice nucleation ability. The effective ice nucleation has been explained by the structural similarity of the AgI surfaces and the basal plane of ice I h . However, the relevant AgI surfaces are polar, i.e., thermodynamically instable. This fact implies the existence of a stabilization mechanism. The nature of this stabilization mechanism remains, however, unknown. Additionally, calculations suggest that exclusively the silver-terminated and not the iodine-terminated surfaces nucleate ice. So far, no atomically resolved images at any AgI-water interface exist. This is most likely du...