Research Article Nanostructured Multilayer Composite Films of Manganese Dioxide/Nickel/Copper Sulfide Deposited on Polyethylene Terephthalate Supporting Substrate Awangku Nabil Syafiq Bin Awangku Metosen, Suh Cem Pang, and Suk Fun Chin Department of Chemistry, Faculty of Resource Science and Technology, Universiti Malaysia Sarawak, 94300 Kota Samarahan, Sarawak, Malaysia Correspondence should be addressed to Suh Cem Pang; suhcem@gmail.com Received 23 January 2015; Accepted 29 March 2015 Academic Editor: Gaurav Mago Copyright © 2015 Awangku Nabil Syafq Bin Awangku Metosen et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Nanostructured multilayer manganese dioxide/nickel/copper sulfde (MnO 2 /Ni/CuS) composite flms were successfully deposited onto supporting polyethylene terephthalate (PET) substrate through the sequential deposition of CuS, Ni, and MnO 2 thin flms by chemical bath deposition, electrodeposition, and horizontal submersion deposition techniques, respectively. Deposition of each thin-flm layer was optimized by varying deposition parameters and conditions associated with specifc deposition technique. Both CuS and Ni thin flms were optimized for their electrical conductivity whereas MnO 2 thin flm was optimized for its microstructure and charge capacity. Te electrochemical properties of nanostructured multilayer MnO 2 /Ni/CuS composite flms were evaluated by cyclic voltammetry as electrode materials of an electrochemical capacitor prototype in a dual-planar device confguration. Cyclic voltammogram in mild Na 2 SO 4 aqueous electrolyte exhibited a featureless and almost rectangular shape which was indicative of the ideal capacitive behavior and high cycling reversibility of the electrochemical capacitor prototype. Nanostructured multilayer MnO 2 /Ni/CuS composite flms on supporting polyethylene terephthalate (PET) substrate could potentially be utilized as electrode materials for the fabrication of high performance electrochemical capacitors. 1. Introduction Generally, the fabrication of thin-flm electrochemical capac- itor entails the deposition of an electroactive thin flm onto an electrically conductive supporting substrate which serves collectively as both the current collector and the supporting substrate. A gel electrolyte layer which serves as the ion- ically conductive medium is subsequently added between the electrodes of electrochemical capacitor. Nanostructured manganese dioxide thin flms have been comprehensively studied in recent years in order to determine the relations among their morphological, structural, and compositional characteristics for enhancing performance of electrochem- ical capacitors [1]. Methods commonly used for deposit- ing nanostructured manganese dioxide thin flms include anodic oxidation, electrodeposition, electroless deposition, successive ionic layer adsorption and reaction (SILAR), chemical bath deposition, electron beam evaporation, chem- ical vapor deposition, reactive sputtering, molecular beam epitaxy, pulsed layer deposition, and atomic layer deposition [2]. However, chemical deposition methods which involve growth from solution are more favorable as they are cost- efective, and thin flms of complex chemical compositions can be formed at low deposition temperature. Such low depo- sition temperature is highly desirable in order to avoid efects such as interdifusion, contamination, and dopant redistri- bution. Besides, the morphology of thin flms deposited can be easily controlled via optimizing preparative parameters. Unlike physical deposition methods, chemical deposition methods do not require high quality target or substrates nor do they require vacuum at any stage of deposition process [3]. Te self-assembly horizontal submersion process and the electrophoretic deposition method have been demonstrated to be versatile and cost-efective deposition techniques for the Hindawi Publishing Corporation Journal of Nanomaterials Volume 2015, Article ID 270635, 11 pages http://dx.doi.org/10.1155/2015/270635