Nanoporous gold film fabricated by capillary-flow-induced deposition of gold nanoparticles

摘要

We present a facile method for preparation of nanoporous gold films using a simple wet chemical method. Suspended droplets of the mixture contained tetrachloroauric (III) acid and sodium formate were deposited on the surfaces of cylindrical PDMS disk. The fabricated nanoporous gold films on the PDMS disk exhibited superhydrophobic property with the water contact angle as large as 167°. Systematic characterization revealed that Marangoni flows involves in the formation of the nanoporous superhydrophobic gold films. The temperature gradients originated from evaporation of solution at the droplet surfaces induces the smooth flow inside the droplets facilitating the homogeneous deposition and growth of gold particles on the surface of PDMS. The fabricated nanoporous gold films were employed as high performance SERs substrates which could provide clear characteristic SERS spectrum of 10~7 M R6G.