International Journal of Environment & Water ISSN 2052-3408 ______________________________________________________________________________ Vol 2, Issue 2, 2013 111 Page Photocatalytic activity of silvered zinc oxide stabilized on cotton fiber for methylene blue dye decolorization Amjed Mirza Oda1,Salih Hadi Kadhum2, Ahmed Salih Farhood2, Hussain Abdul alkadhum2 University of Babylon, College of Basic Education, Science Dept. 1 University of Babylon, Science College, Chemistry Dept. Abstract In this research, a non- conventional method for photocatalytic decolorization of waste water contaminants like methylene blue. Zinc oxide was doped with silver ion by photodeposition process and characterized by XRD and FTIR analysis. Fabric of cotton was used as carier and stabilizer of ZnO/Ag+. This group was tested for photocatalytic activity using methylene blue dye and artificial uv. light. Fabric was efficient in photodecolorization of methylene blue dye in the presence of uv. light Keywords: photocatalytic decolorization, Zinc oxide, photodeposition, methylene blue. Introduction Methylene blue (MB) dye, among various dyes, is difficult to degrade and is often utilized as a model dye contaminant to evaluate the activity of a photocatalyst both under ultraviolet light irradiation and under visible light irradiation (Jingfei Luan et al 2012) . The conventional technologies currently used to degrade the color of the dye contaminated water include primary (adsorption, flocculation), secondary (biological methods), and chemical processes (chlorination, ozonization). However these techniques are non- destructive, since they only transfer the non- biodegradable matter into sludge, giving rise to new type of pollution, which needs further treatment (Bansal et al 2012). Heterogeneous photocatalysis is a technique of environmental interest for the treatment of polluted water combining the low cost, the mild conditions and the possibility of using sunlight as the source of irradiation (Chong et al., 2010; Ahmed et al., 2011) This technique is based on the irradiation of semiconductor particles, usually suspended in aqueous solutions, with wavelengths eŶergLJ hǀ≥Eg ;ďaŶd gap eŶergLJͿ, proŵotiŶg an electron e - from the valence band to conduction band, remaining a positive hole h + in the valence band. The electron–hole pairs (e - /h + ) thus generated can migrate to the surface of the photocatalyst and can either recombine producing thermal energy or serve as the oxidizing and reducing agents. The photocatalytic degradation of compounds is largely dependent on the solution pH, pollutant type and concentration, UV light intensity, catalyst loading, ionic composition of wastewater and oxidant concentration. In addition, surface and structural properties of semiconductor, such as crystal composition, surface area, particle size distribution, porosity, band gap and surface hydroxyl density, are parameters influencing degradation of these organic compounds (Ahmed et al., 2011). Rapid recombination of photo-excited electrons and holes greatly impedes the photocatalytic efficiency of ZnO. To overcome this limitation, modification with noble metals, metal oxides, metal sulfides, transition metals and other components have all been studied. Among them, Ag is considered to be an interesting doping element since it can effectively trap the photo-excited electrons from the semiconductor to liberate the holes(Tianxi Liu et al, 2011). Experimental