Hydrothermal ZnO Nanorod Array Growth

ZnO nanorod arrays for solar cells, nanogenerators and gas sensors are grown from a simple aqueous bath, but the mechanism that turns a seeded flat substrate into a forest of vertically-aligned hexagonal rods is a facet-selective competition: the polar Zn-terminated (0001) tip accepts growth units far faster than the six nonpolar side facets, so seed crystallites elongate rather than fatten. This simulator models that race explicitly — an InstancedMesh of hexagonal wurtzite prisms grows on a seeded substrate under a live Arrhenius-plus-supersaturation rate law, with temperature and precursor concentration driving both facets and a citrate capping-agent slider selectively throttling only the radial one, exactly as it does in a real synthesis bath.