صدیقه هاشم نیا

Green synthesis of palladium nanoparticles embeded on zinc oxide support (Pd/ZnO) and unsupported palladium nanoparticles were done using systoseira brown algae gathered from persian gulf shores. Chemical compounds in this algae have hydroxyl, carboxyl and amine functional groups that help in reduction of Pd2 ions to Pd nanoparticles and also help in their stabilization. Pd/ZnO nanoparticles were characterized by XRD, EDAX and FESEM methods. The shape of these nanoparticles were determined through HRTEM analysis. XRD pattern showed that Pd/ZnO was crystallized in cubic structure with 4.9 nm crystallite size and zinc oxide was crystallized in hexagonal structure with 21 nm crystallite size. The shapes of zinc oxide nanoparticles are flower-like and Pd nanoparticles were spherical.Unsupported Pd nanoparticles were characterized by XRD method, and it was shown that they were crystallized in....structure with...crystallite size. The Pd/ZnO nanoparticle modified carbon paste electrode and Pd nanoparticle modified carbon paste electrode were used for detection and oxidation of ethanol. Cyclic voltametry and chronoamperometry were used for this study. The results showed that the reactivity and the stability of Pd/ZnO nanoparticles were higher than Pd nanoparticles in oxidation of ethanol. It was also showed that Pd/ZnO is a non-enzymatic sensor for detection of ethanol. This methode had a detection limit of 0.15 mM and its linear range is 170-560 mM. These results showed that Pd/ZnO nanoparticle is a good candidate for application as sensor for ethanol and also as a convenient catalyst for application in ethanol fuel cells.