Interfacial Anchoring of CeO2 on Cu(OH)2 Nanoneedle Arrays for Corrosion-Resistant and Patternable SuperhydrophobicCopper Surfaces.

Conventional superhydrophobic copper surfaces typically rely on organic or fluorinated low-surface-energy modifiers, complicating fabrication and raising environmental concerns. Here, patternable superhydrophobic copper surfaces were fabricated by electrodepositing CeO2 onto in situ-grown Cu(OH)2 nanoneedle arrays. The arrays provided preconstructed rough scaffolds and favorable interfaces for CeO2 loading. CeO2 deposition preserved the integrity of the nanoneedle framework while introducing additional surface roughness. Subsequent vacuum heating promoted surface dehydration and dehydroxylation, thereby reducing the affinity of the surface for water. These changes, together with hierarchical roughness and the relative enrichment of nonpolar carbonaceous species, promoted the formation of a low-adhesion superhydrophobic state. The resulting surface exhibited a water contact angle of 157.6° and a water droplet adhesion force of 21.4 μN, together with mechanical durability, self-cleaning ability, and a corrosion inhibition efficiency of 99.162% in chloride-containing media. Selective heat treatment enabled the fabrication of patterned superhydrophilic/superhydrophobic regions, and the method was extended to copper mesh and copper foam. This work provides a strategy for constructing structurally controlled, multifunctional superhydrophobic protective surfaces without intentionally added organic or fluorinated modifiers.