Nature Communications (2026). DOI: 10.1038/s41467-026-71053-3"> Atomistic models, water orientation definitions, and computational workflow. Credit: Nature Communications (2026). DOI: 10.1038/s41467-026-71053-3 For more than a decade, a fundamental mystery has surrounded graphene—the one-atom-thick "wonder material" known for its exceptional strength, conductivity, and transparency. Despite its seemingly simple structure, one basic question has remained unresolved: Does graphene attract water, or repel it? The answer has proven surprisingly elusive. In some experiments, water droplets bead up on graphene, suggesting a hydrophobic (water-repellent) surface. In others, water spreads out, implying hydrophilic (water-attracting) behavior. This contradiction has fueled a long-running scientific debate and created uncertainty for applications such as desalination membranes, hydrogen fuel cells, and nanoelectronic devices, where precise control of water at interfaces is essential.…