Silver Oxide Thermolability: Decoration of Oxides Substrate Surfaces with Silver Nanoparticles

MICAELA A. MACCHIONE; NICOLÁS PASSARELLI; OSCAR A. DOUGLAS GALLARDO; RAQUEL MOIRAGHI; EDUARDO A. CORONADO; VICENTE A. MACAGNO; MANUEL A. PÉREZ; MIGUEL JOSÉ-YACAMÁN

San Antonio, Texas

Conferencia; College of Science Research Conference 2015; 2015

Aqueous silver oxide colloidal (Ag2O) decomposes at 25° C forming silver nanoparticles (AgNPs) and H2O2/O2. This process is accelerated by temperature and the decrease of the medium polarity (mixture acetone: water) allows to obtain AgNPs with different sizes and morphologies. Based on this background, our research group has recently developed a synthetic method for decorating substrates as oxides microparticles (OMPs) of SiO2 and TiO2 with AgNPs, producing hybrid nanostructures (OMPs|AgNPs like SiO2MPs|AgNPs and TiO2MPs|AgNPs) by decomposition Ag2O. Thus, production of these nanostructures is performed by: first, the deposition of Ag2O takes place on the OMPs?s surface and then, the thermal decomposition of Ag2O allows to obtain the AgNPs directly adhered to OMPs. Our strategy is based on the assumption that the Ag2O have a greater adhesion to the OMPs substrate than the one which exhibits metallic silver. The results show that the control of variables allows that the Ag2O nucleation occurs heterogeneously mostly over the OMPs substrate, allowing to produce mainly hybrid nanostructures instead of AgNPs isolated. This makes unnecessary an extra substrate functionalization step, resulting in a considerable simplification of the synthesis. This synthetic route has important advantages: materials and equipment for low cost, low power consumption, simple and safe procedures, easy purification of nanostructures. The focus of this work is to deepen the characterization of the interface OMPs|AgNPs by using electron microscopy techniques. [1] O. A. Douglas-Gallardo, R. Moiraghi, M. A. Macchione, J. A. Godoy, M. A. Pérez, E. A. Coronado, V. A. Macagno, RCS Adv., 2 (2012), 2923-2929. [2] M. A. Macchione, O. A. Douglas-Gallardo, L. A. Pérez, N. Passarelli, R. Moiraghi, A. Spitale, D. Bahena, F. Y. Oliva, M. M. Mariscal, M. José-Yacamán, E. A. Coronado, V. A. Macagno, M. A. Pérez, J. Colloid Interface Sci. 428 (2014) 32?35.