Electrochemical Codeposition of Thin Gold Nanoparticles/Sol−Gel Nanocomposite Films

Abstract

We present a new method for deposition of thin nanocomposite films made of sol-gel-based Au nanoparticles using a single electrochemical step. Applying a negative potential to an electrode (indium tin oxide or stainless steel) immersed in a solution of gold nanoparticles stabilized with N- [3-(trimethoxysilyl)propyl] ethylenediamine (EDAS) caused the reduction of the protic solvent, which altered the pH and therefore catalyzed the deposition. The nanocomposite thin films were characterized by various techniques: the morphology and structure of the layers were examined by high-resolution scanning electron microscopy and atomic force microscopy; their thickness was determined by profilometry; and the permeability of the films was studied by electrochemistry. We found that homogeneous defect-free layers could be deposited only upon adding tetramethoxysilane (TMOS) to the deposition solution. Furthermore, we showed that the applied potential, the ratio between the TMOS and the Au nanoparticles, and the type of the substrate significantly affected the aggregation and density of the Au nanoparticles in the nanocomposite. Finally, by applying a positive potential to the nanocomposite films we succeeded to electrochemically dissolve the embedded Au nanoparticles, forming holes and channels. The oxidation treatment had a remarkable effect on the permeability of the film and exposed the electrode to faradic activity. This method seems to be of general applicability in templating of nanometer-sized objects in thin films.

Nanocomposite Coatings: Preparation, Characterization, Properties, and Applications

“…By this sol-gel process, Facio and Mosquera [38] also successfully fabricated the nanocomposite coatings containing (i) a mixture of monomeric and oligomeric ethoxysilanes, (ii) a hydroxyl-terminated polydimethylsiloxane, (iii) colloidal silica particles, and (iv) a surfactant (n-octylamine). In addition, the sol-gel method could be used in combination with the electrodeposition for incorporation of inorganic nanofillers into the organic matrix [78] or into inorganic matrix [84].…”

“…For inorganic nanofillers, the types of nanoparticles are carbides [58], nitrites [59][60][61][73][74][75][76][77], borides [55], oxides [4,5,62,65], metallic particles [17,78], clay [4,5,35], CNT [54], and nanodiamond [56,79]. For organic nanoparticles (organic nanofiller), the most used nanoparticles were PTFE [80][81][82], PEO [83], PANi [31], or nanocellulose and cellulose nanocrystal [18,40].…”

Formation, Characterization, and Applications of Organic and Inorganic Nanometric Films

“…We have shown that the formation of a sol-gel layer can be accompanied by another process, such as metal deposition, electropolymerization, and the incorporation of nanoparticles. [40,41] Figure 7 shows the co-deposition of copper and silica on an electrode surface. The copper ions were electrochemically reduced simultaneously with the reduction of protons and elevation of pH.…”

Electrocatalytic Performance of SiO2-SWCNT Nanocomposites Prepared by Electroassisted Deposition

“…A simple way could be the immobilization of the material inside a porous inorganic matrix. Some reports show how carbon nanotubes or nanoparticles can be dispersed in mesoporous SiO 2 structures obtained by either chemical vapor deposition [21][22][23] or sol-gel methods [24][25][26][27][28] .…”