Hindawi Publishing Corporation Journal of Nanomaterials Volume 2013, Article ID 157810, 5 pages http://dx.doi.org/10.1155/2013/157810 Research Article Optical and Electrical Studies of Polyaniline/ZnO Nanocomposite Manawwer Alam, 1 Naser M. Alandis, 2 Anees A. Ansari, 3 and Mohammed Rafi Shaik 2 1 Research Center, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia 2 Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia 3 King Abdullah Institute for Nanotechnology, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia Correspondence should be addressed to Manawwer Alam; malamiitd@gmail.com Received 22 September 2013; Accepted 9 December 2013 Academic Editor: John Zhanhu Guo Copyright © 2013 Manawwer Alam et al. his 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. Polyaniline (Pani)/ZnO nanocomposite with diameter 40–50nm was successfully fabricated by coprecipitation method of ZnO via in situ polymerization of Pani. X-ray difraction (XRD), high resolution transmission electron microscopy (HRTEM), fourier transformation infrared (FT-IR), UV-Vis absorption spectra, thermogravimetric analysis (TGA), and electrical properties were studied. HRTEM studies showed that the prepared ZnO nanoparticles were uniformly dispersed and highly stabilized throughout the polymer chain and formed uniform metal oxide-conducting polymer nanocomposite material. UV-Vis spectra of Pani/ZnO nanocomposite were studied to investigate the optical behavior ater doping the ZnO nanoparticle into the polymer matrix. he inclusion of ZnO nanoparticle gives rise to the red shit of - ∗ transition of Pani. he nanocomposite was found to be thermally stable upto 130 ∘ C and showed conductivity value of 3.0 × 10 −2 Scm −1 . 1. Introduction Pani, a conducting polymer, has increasing scientiic and technological interests in the synthesis of a broad variety of promising materials due to its unique electrical and optical properties [1, 2]. Pani is widely used in the area of electro- chemical materials, light-emitting diodes, biosensors, chem- ical sensors, and battery electrodes [3–5]. Recently, extensive research has been focused on the synthesis and potential applications in electronic devices to enhance the electrical properties of Pani [6]. Numerous eforts have been made to successfully prepare nanocomposites by chemical and electrochemical prepara- tion methods using nanostructured metal oxides namely TiO 2 , SnO 2 , SiO 2 , CeO 2 , and Fe 2 O 3 due to their unique electrocatalytic, piezoelectric, and photonic properties and tunable size that make them suitable for solar cell applications [7–11]. hese nanocomposites show quite diferent properties than the individual materials. Nanostructured zinc oxide (ZnO) has unique properties like high isoelectric point, transparent n-type semiconductor with direct wide band gap (3.37 eV), biocompatibility, nontoxicity, high chemical stabil- ity, high electron transfer capability, and others [12–18] with various potential applications such as in gas sensor, biological sensor, ultraviolet light emitting diodes, dye sensitized solar cells, photocatalysis, ceramics, cosmetics, and paint industry [19–31]. In the present work, we report the synthesis of ZnO nanoparticle and ZnO nanoparticle doped in Pani using coprecipitation method and observed the optical, electrical, and thermal properties of Pani/ZnO nanocomposite. he prepared Pani/ZnO nanocomposite was characterized by FT- IR, XRD, UV-Vis, TGA, and conductivity studies. 2. Experimental 2.1. Materials. Aniline and Zinc acetate (BDH chemical Poole, England) were distilled under reduced pressure be- fore use. Ammonium peroxodisulfate (APS), Ammonium hydroxide (Merck, India), and other chemicals used were of