Characterization of Zn(1-x)Co(x)O Nanomaterials for Fuels Cells Applications

Characterization of Zn(1-x)Co(x)O Nanomaterials for Fuels Cells Applications

Dinorah Martínez-Torres, Suheily Alonso-Sevilla, Ana G. Estrada-Álvarez, Alejandra Sánchez-Zalduondo, Astrid M. Rodriguez-Rodriguez; Natalia I. Román-Montalvo, Rahul Singhal and Mitk’El B. Santiago-Berríos

Transition metal oxides have attracted interest in recent years. This interest for Zinc oxide (ZnO) materials is because they are easy to synthesize and have been used in different applications such as medicine, sensors, and solar energy harvesting applications. ZnO materials also have shown that could be used as an alternative for the oxygen reduction reaction. This project will study the effect of doping agents in the crystal structure of zinc oxide nanomaterials. ZnO has a band gap of 3.37 eV.  The Diffuse Reflectance of the doped materials showed new bands at 3.26-2.30eV, 2.20eV, 2.05eV and 1.90eV. Raman spectroscopy showed more intense, broad, and symmetric mode appears at around 472 cm-1 to 700 cm-1. These results indicate the quasi-longitudinal-optical (LO) phonon mode, where the abundant shallow donor defects are bounds on the Co sites.  Our preliminary results have demonstrated that cobalt immersion in the crystal structure of ZnO allows the formation of new energy levels that can be used as a catalyst for the reduction of oxygen into water molecules. This was demonstrated since the reduction peak for the cobalt (III) to cobalt (II) appears at around -410 mV vs. Ag/AgCl. This poster will present the complete characterization using X-ray techniques, Raman spectroscopy and electrochemistry.