Preparation of a Superhydrophobic Ni Complementary Surface Using a Walnut Wood Template

Ni is widely used in the field of corrosion protection because of its stability, hardness, and ductility. Inspired by the excellent hydrophobicity of walnut wood, imparted by its porous structure, we synthesized a morph-genetic, porous Ni sheet. A pyrolyzed walnut template was immersed in a Ni²⁺ solution, allowing Ni to be electroplated on the surface and to enter the skeleton's pores. After calcination and surface modification, a template-free, low-surface-energy Ni sheet was obtained and accurately investigated by scanning electron microscopy and contact angle goniometry to evaluate its morphology and hydrophobicity. The results show that the Ni sheet inherited the complementary structure of the template, and, in turn, its water-repelling ability. We were able to measure contact angles as large as 150°, demonstrating that the new surface morphology endowed Ni with superhydrophobicity.