Preparation and hydrophobicity of biomorphic ZnO/carbon based on a lotus-leaf template

A lotus leaf was used as a template to fabricate superhydrophobic biomorphic ZnO on a carbon substrate (ZnO/C). First, a carbon substrate with the microstructure of a leaf surface was obtained by sintering a lotus leaf in argon. A biomorphic ZnO/C material was then obtained by immersing this carbon substrate into a Zn(NO3)2 solution and sintering. Finally, the hydrophobicity of the surfaces of the products thus obtained was investigated. This ZnO/C material exhibited excellent superhydrophobicity and low adhesion after it was modified with fluorine silane. The water contact angle of the resulting product was 162°, which exceeds that of the lotus leaf (157°) and is much higher than that of smooth carbon covered with the same fluorine silane (114°). Moreover, this surface displayed a stable superhydrophobic performance even after exposure to ambient air for several months.