High surface area electrodes by template-free self-assembled hierarchical porous gold architecture Ahiud Morag a,b , Tatiana Golub a , James Becker a , Raz Jelinek a,b,⇑ a Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel b Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel graphical abstract article info Article history: Received 18 February 2016 Revised 13 March 2016 Accepted 16 March 2016 Available online 17 March 2016 Keywords: Porous gold Supercapacitors Gold thiocyanate Plasma abstract The electrode active surface area is a crucial determinant in many electrochemical applications and devices. Porous metal substrates have been employed in electrode design, however construction of such materials generally involves multistep processes, generating in many instances electrodes exhibiting incomplete access to internal pore surfaces. Here we describe fabrication of electrodes comprising hierarchical, nano-to-microscale porous gold matrix, synthesized through spontaneous crystallization of gold thiocyanate in water. Cyclic voltammetry analysis revealed that the specific surface area of the conductive nanoporous Au microwires was very high and depended only upon the amount of gold used, not electrode areas or geometries. Application of the electrode in a pseudo-capacitor device is presented. Ó 2016 Elsevier Inc. All rights reserved. 1. Introduction Electrode performance, particularly the electrode’s active sur- face area, is a critical factor in many applications, including super- capacitors [1–3], batteries [4,5], solar cells [6,7], and sensors [8,9]. Porous gold structures have attracted growing interest as a versa- tile electrode substance [10–14], and in related applications such as sensing and catalysis [15–19]. A particular focus of current research in this field is to increase the effective surface area of porous gold matrixes by integrating morphologies in different length-scales, e.g. from nano- to macro-structures [20–22]. While such hierarchical Au scaffolds have promising functionalities as they exhibit high surface areas, their fabrication methods are cum- bersome and involve complex processes. In some cases physical http://dx.doi.org/10.1016/j.jcis.2016.03.035 0021-9797/Ó 2016 Elsevier Inc. All rights reserved. ⇑ Corresponding author at: Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel. E-mail address: razj@bgu.ac.il (R. Jelinek). Journal of Colloid and Interface Science 472 (2016) 84–89 Contents lists available at ScienceDirect Journal of Colloid and Interface Science journal homepage: www.elsevier.com/locate/jcis