Abstract

DIAZ, C.; VALENZUELA, A. M. L.; SOTO, K.  and  LAGUNA-BERCERO, M. A.. INCORPORATION OF AU AND AG NANOSTRUCTURES INSIDE SIO₂. J. Chil. Chem. Soc. [online]. 2019, vol.64, n.3, pp.4502-4506. ISSN 0717-9707.  http://dx.doi.org/10.4067/S0717-97072019000304502.

Incorporation of Au° inside SiO2 was achieved by a solid-state method from the pyrolysis of the composites (Chitosan)•(AuCl3)n•(SiO2)m and (PS-co-4-PVP)•(AuCl3)n•(SiO2)m Similarly, the incorporation of Ag° inside SiO2 it was made from thermal treatment of the composites (Chitosan)•(AgNO3)n•(SiO2)m and (PS-co-4-PVP)•(AgNO3)n•(SiO2)m. The nature of the polymer controls the particle size for the Au/SiO2 composite, while that for the Ag/SiO2 both, polymer Chitosan and PS-co-4-PVP, produces similar particle size. In the case of the composite Ag/SiO2 the particle size as small as 5 nm were obtained.

The 1:1 or 1:5 metal/polymer ratios, as well as the nature of the polymer in the macromolecular precursors (Chitosan)•(AuCl3)n•(SiO2)m and (PS-co-4-PVP)•(AuCl3)n•(SiO2)m influences the dispersion of the Au° nanostructures inside SiO2 matrix. The results are compared with those previously obtained for bimetallic composites Au/Ag//SiO2. A formation mechanism of the Au°/SiO2 and Ag°/SiO2 composites involving the combustion of the organic matter and the growth of the Au° and Ag° nanoparticles inside the holes, generated from the combustion process, is proposed.

Keywords : Gold nanoparticles; Silver nanoparticles; silica; composites.

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