Electrodeposited gold nanoparticles on carbon nanotube-textile: Anode material for glucose alkaline fuel cells Mauro Pasta, Liangbing Hu, Fabio La Mantia, Yi Cui ⁎ Department of Materials Science and Engineering, Stanford University, 94305 Stanford, CA, USA abstract article info Article history: Received 25 February 2012 Received in revised form 6 March 2012 Accepted 12 March 2012 Available online 21 March 2012 Keywords: Glucose electrooxidation Conductive textiles Gold electrocatalysis Glucose fuel cell In the present paper we propose a new anode material for glucose–gluconate direct oxidation fuel cells prepared by electrodepositing gold nanoparticles onto a conductive textile made by conformally coating single walled carbon nanotubes (SWNT) on a polyester textile substrate. The electrodeposition conditions were optimized in order to achieve a uniform distribution of gold nanoparticles in the 3D porous structure of the textile. On the basis of previously reported studies, the reaction conditions (pH, electrolyte composition and glucose concentration) were tuned in order to achieve the highest oxidation rate, selectively oxidizing glucose to gluconate. The electrochemical characterization was carried out by means of cyclic voltammetry. © 2012 Elsevier B.V. All rights reserved. 1. Introduction The direct oxidation of glucose to produce electrical energy has been widely investigated because of renewability, abundance, high energy density and easy handling of the carbohydrate. Most of the earlier studies have been conducted in extreme conditions in order to achieve glucose complete oxidation to CO 2 , neglecting the carbohy- drate chemical instability that generally leads to useless by-product mixtures [1]. The partial oxidation to gluconate, originally studied for implantable fuel cells, has the advantage of generating a commer- cially valuable chemical [2]. In a previous study we characterized a commercial platinum based anode material, optimizing the operating conditions in order to selectively oxidize glucose to gluconate under alkali conditions, maximizing the current output [3]. The aim was also to produce an actual benchmark for the evaluation of new electrode materials. In this sense, gold has been demonstrated to be more active than platinum towards glucose electrooxidation in an alkali environment [4]. In order to improve our knowledge of the system, we first studied the mechanism of glucose electrooxidation at gold electrodes [5] and outlined the outstanding electrocatalytic properties of gold nanopar- ticles [6]. On the basis of these studies, here we propose a new anode material based on gold nanoparticles electrodeposited on conductive textiles prepared by conformally coating SWNT on a polyester matrix [7,8]. The tridimensional macroporous structure of the textile backbone accounts for both higher metal mass loading per geometri- cal surface area and easier substrate diffusion while the microporosity of the CNT layer improves gold adhesion. 2. Experimental section Sodium dodecylbenzene sulfonate (SDBS), sodium fluoride (99%, Alfa Aesar), D-(+)-dextrose (Sigma Aldrich), sodium phosphate dibasic anhydrous (99%, EMD), and gold (III) chloride trihydrate (99.9 + %) were purchased from Sigma Aldrich. Nitric acid (68%) and glacial acetic acid were purchased from EMD Chemicals. Fluffy polyester sheets (Texwipe TX309) were purchased from Wal-Mart Inc. Electrochemical characterization was carried out using a BioLogic VMP3 potentiostat–galvanostat multichannel equipped with an electrochemical impendence spectroscopy (EIS) board. A double junction Ag|AgCl|KCl (3.5 M) reference electrode (RE) was used in the measurement. The double junction was employed to prevent OH - diffusion and reaction at the Ag|AgCl interface. In addition, the RE potential was monitored after each measurement to confirm that no change had taken place. All the measurements were performed under inert (nitrogen) atmosphere and at room temperature. 2.1. Conductive textile fabrication Conductive textiles are produced by a simple dip and dry process of a SWNT ink on a fluffy polyester textile. We refer to our previous paper [8] for a detailed description of preparation procedure and physicochemical characterization of the material. Electrochemistry Communications 19 (2012) 81–84 ⁎ Corresponding author. E-mail address: yicui@stanford.edu (Y. Cui). 1388-2481/$ – see front matter © 2012 Elsevier B.V. All rights reserved. doi:10.1016/j.elecom.2012.03.019 Contents lists available at SciVerse ScienceDirect Electrochemistry Communications journal homepage: www.elsevier.com/locate/elecom