Obtenção de prata nanoestruturada a partir da redução mecano-química de 𝐴𝑔2𝑂

Abstract

The mixture of the precursor element Ag2O with three different process control agents (carbon, glycerine and polyethylene), each mixture called route 1, route 2 and route 3 respectively, were synthesized using the mechanochemical technique. In all synthesis routes the silver oxide was reduced in silver, but one route with greater efficiency than another. The evolution of the structural properties of the samples for the routes of the process control agents (PCA) was studied by the X - ray diffraction (XRD) technique, at each time interval of mechanochemical synthesis a measurement of XRD was performed. The presence of silver carbonate (contaminant) in all ACP routes was identified, with increasing milling time there is a decrease but not dissipation. From the structural refinements by the Rietveld method using the GSAS software, the average crystallite size of routes 1, route 2 and route 3 was estimated, where the mean crystallite size for each route at the end of the synthesis was 13 nm, 22 nm and 12 nm, respectively. Differential Scanning Calorimetry (DSC) analysis was performed on all samples for thermal stability analysis. The heat treatment was carried out for one hour at 300 ° C under inert atmosphere, the XRD measurement was performed on the residue, which revealed dissipation of the silver carbonate. The morphology of the synthesized samples was investigated using scanning electron microscopy (SEM), the technique was applied in the untreated and thermally treated samples, route 1 shows a leaf shape morphology and the flake shape route 2, both with size of irregular grains. The FTIR technique was applied to identify if there were still organic compounds in nanostructured silver.