Fabrication and Superhydrophobic Property of ZnO Micro/Nanocrystals via a Hydrothermal Route

Abstract

Superhydrophobic ZnO micro/nanocrystals were fabricated on a large scale using a facile one-pot hydrothermal process successfully. The morphologies and chemical composition of as-synthesized ZnO were investigated by the scanning electron microscope (SEM) and X-ray powder diffraction (XRD). The morphology of ZnO products changed from uniform size microrods to flower-like micronanostructures, when the temperature changed from 120°C to 180°C. The morphology of ZnO was strongly affected by the pH. The wettability of the as-synthesized ZnO micro/nanocrystals was studied by measuring water contact angle (CA). The largest static CA for water is 167°, which is closely related to both the ZnO micro/nanostructure and chemical modification. Furthermore, the as-prepared ZnO surface showed superhydrophobicity for some corrosive liquids such as basic and acidic aqueous solutions. The CAs of the surface modified with ZnO prepared at 160°C were over 155° in the range of pH = 1–13.

Recent Advances in the Methods for Designing Superhydrophobic Surfaces

“…Templating [3,[10][11][12][13][14][15][16][17][18][19][20][21][22][23] Electrospinning [24][25][26][27][28][29][30][31][32][33][34][35] Hydrothermal synthesis [38][39][40][41][42][43][44] Sol-Gel [45][46][47][48][49][50][51][52] Layer by layer method [45,[54][55][56][57][58][59][60][61] Physical and chemical vapour deposition methods…”

“…Various polymeric supports, such as polyethylene glycol, are typically used for the improvement of topological properties. These supports, when adsorbed on the metal substrates, inhibit the crystal growth on certain spots and provide micro/ nanoroughness to the material [39]. Hydrothermal process with only ultra-pure water as the reaction medium is a green technique and efficient in the production of complex biomimics with rough textures directly on metal surfaces.…”