Synthesizing nano particles of WO3 preparde via reverse micelle method

Over the past few years, much effort has been devoted to th e synthesis of semiconductor nanowires, nanorods, and nanobelts,because of the importance of understanding the dimensionality confined transport phenomena and fabricating nanodevices and nanosensors [1]. Tungsten trioxide (WO3) has been the subject of great interest as a result of its special electrochromic gas sensing and catalytic propertiesFor these applications the morphological characteristics of the materials, such as grain size or shape, are very important and depend strongly on the preparation method. Nanopowders of WO3 have been prepared by sol-gel, spray pyrolysis, and radio frequency magnetron sputtering.[2] The particles prepared in reverse micellar solution are generally very fine and monodispersed. Many kinds of nanoparticles have been obtained in reverse micellar solution [3-6], including metals , metal oxides,Tungstane oxide nanoparticles have been synthesized using microreactors made of bis-(2-ethylhexyl)sulfosuccinate (AOT)/water/n-hexane microemulsions. The control of particle size was achieved by varying the process variables, such as water-to-surfactant molar ratio and reagent concentration. Their sizes, appearances, crystal structures, pore diameter and surface area were characterized by TEM, XRD method. The results revealed that samples prepared in reverse micelles had no crystalline phase. Samples synthesized in reverse micelles had better reaction performance than samples prepared via sol–gel method. A parallel relationship could be drawn between the catalytic activity and the particle size as well as the selectivity of the catalyst. the particle size and shape can be controlled by changing the molar ratio of surfactant/water (w/o)[7-9]