Porous Gold Films Fabricated by Wet-Chemistry Processes

Aymeric Pastre,Nathalie Rolland,Alexandre Boe,Katarzyna Raulin,Remy Bernard,Odile Cristini,Bertrand Grimbert,Fernand Chassagneux

doi:10.1155/2016/3536153

Abstract

Porous gold films presented in this paper are formed by combining gold electroless deposition and polystyrene beads templating methods. This original approach allows the formation of conductive films (2 × 106 (Ω·cm)−1) with tailored and interconnected porosity. The porous gold film was deposited up to 1.2 μm on the silicon substrate without delamination. An original zirconia gel matrix containing gold nanoparticles deposited on the substrate acts both as an adhesion layer through the creation of covalent bonds and as a seed layer for the metallic gold film growth. Dip-coating parameters and gold electroless deposition kinetics have been optimized in order to create a three-dimensional network of 20 nm wide pores separated by 20 nm thick continuous gold layers. The resulting porous gold films were characterized by GIXRD, SEM, krypton adsorption-desorption, and 4-point probes method. The process is adaptable to different pore sizes and based on wet-chemistry. Consequently, the porous gold films presented in this paper can be used in a wide range of applications such as sensing, catalysis, optics, or electronics.

Highlights

The combination of the intrinsic properties of gold and of those of a porous material makes porous gold films (PGFs) an interesting material in many applications
Dip-coating parameters and gold electroless deposition kinetics have been optimized in order to create a three-dimensional network of 20 nm wide pores separated by 20 nm thick continuous gold layers
All the glassware dedicated to the gold nanoparticles embedded in zirconia matrix synthesis is washed with aqua regia prior to use. 3 × 2 cm2 P-doped (5–10 Ω) pieces of Si (100) wafers are used as substrates

Summary

Introduction

The combination of the intrinsic properties of gold and of those of a porous material makes porous gold films (PGFs) an interesting material in many applications These films are conductive [1] and chemically stable [2], present good wettability in electrolyte solutions [3], and exhibit a large specific surface area. PGFs are used as bio/chemical sensing electrode systems [2, 11,12,13,14], based on their nontoxic and biocompatible nature [12] and on the presence of active sites for biomaterials These films present a high electrocatalytic activity, rapid mass transport, and a good thermal stability, which makes them suitable for (electro)catalytic applications [12, 15,16,17]. PGFs exhibit excellent properties concerning Surface-Enhanced Raman Spectroscopy (SERS), Fluorescence, and Surface Plasmon Resonance (SPR), making them an attractive material for optical applications [18,19,20]

Methods

Results

Conclusion