Electrodeposition of Hierarchical Nanostructured Gold Coatings as Facile Route for Fabrication of Superhydrophobic Surfaces

Abstract

Herein electrochemical approaches for fabrication of hierarchical nanostructured gold coatings (HNGCs) are presented. Examples of HNGCs obtained by electrodeposition in sulphite based electrolyte on nickel electroplated copper (Ni/Cu) substrates are reported. The morphology and microstructure of the nanostructured surface were studied by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD). The effects of the electrodeposition current density (J) and deposition time on the morphological features of nanostructured gold coating will be discussed. The surface wettability on thiols treated gold surface as a function of the electrodeposition current density is investigated. Thiols treated electrodepsited HNGCs can possess superhydrophobic behavior with water contact angle of 179 °. IntroductionSuperhydrophobic surfaces exhibit a number of exciting properties, which have attracted a lot of interest recently and make them important to a wide range of applications, from microfluidics and lab-on-a-chip devices to biomolecule immobilization and self-cleaning coatings (1,2). Conventionally, super-hydrophobic surfaces have been obtained by enhancing surface roughness or by deposition of low surface energy materials (3). The effect of roughness on hydrophobicity has been described by Wenzel's model and Cassie's model. Based on these models, previous studies suggested that small scale (nanoscale) features with a larger scale spacing (microscale) would yield better hydrophobic property (4). Many methods have been developed to produce rough surfaces for hydrophobicity, including plasma etching, anodic oxidization, chemical vapor deposition, phase separation and molding (5). Hierarchical micro/nanostructures assemblies using micro/nanoparticles, nanorods, nanobelts as building blocks with welldefined shape and inner structure can be obtained through colloidal chemistry strategy. Electrochemical deposition methods are widely used to form rough structures. Although electrodeposition is a general route to fabricate hierarchical micro/nanostructures, most of which are synthesized in the presence of organic additives or surfactants, and others are based on template.

Nanostructured Gold for Immobilization of Thioaniline Functionalized Glucose Oxidase and Au Nanoparticles by Electropolymerization

“…In electrodeposition, various morphological patterns of deposited layer can be obtained by controlling the reaction conditions, such as applied potential, electrolyte concentration, electrolyte pH (6). Applied current density is also an key factor to modulate the morphologies of deposited layer.…”

“…Although electrodeposition is a general route to fabricate hierarchical micro/nanostructures, most of which are synthesized in the presence of organic additives or surfactants, and others are based on template. In present work, a facile electrochemical approaches for fabrication of hierarchical nanostructured gold coatings (HNGCs) was studied (6).…”

Simultaneously Fabricating Multifunctional Superhydrophobic/Superoleophilic Coatings by One-Step Electrodeposition Method on Cathodic and Anodic Magnesium Surfaces

“…[22][23][24] Currently, a large number of published works are focused on fabricating superhydrophobic films on cathodic surfaces by electrodeposition method. [25][26][27][28] Unfortunately, few published literature concerned simultaneous preparation of superhydrophobic/superoleophilic coatings on cathodic and anodic surfaces through a one-step electrodeposition process. 29,30 Therefore, if such coatings could be simultaneously fabricated on both of the cathodic and anodic surfaces in single one-step method, the conventional multi-step procedure could be simplified, with the fabrication efficiency improved.…”