Articulo
EXAFS and DFT study of the cadmium and lead adsorption on modified silica nanoparticles
Registro en:
issn:1386-1425
Autor
Arce, Valeria Beatriz
Gargarello, Romina M.
Ortega, Florencia
Romañano, Virginia
Mizrahi, Martín D.
Ramallo López, José Martín
Cobos, Carlos Jorge
Airoldi, Claudio
Bernardelli, Cecilia Elena
Donati, Edgardo Rubén
Mártire, Daniel Osvaldo
Institución
Resumen
Silica nanoparticles of 7 nm diameter were modified with (3-aminopropyl) triethoxysilane (APTES) and characterized by CP-MAS <sup>13</sup>C and <sup>29</sup>Si NMR, FTIR, zeta potential measurements, and thermogravimetry. The particles were shown to sorb successfully divalent lead and cadmium ions from aqueous solution. Lead complexation with these silica nanoparticles was clearly confirmed by EXAFS (Extended X-ray Absorption Fine Structure) with synchrotron light measurements. Predicted Pb–N and Pb–C distances obtained from quantum-chemical calculations are in very good agreement with the EXAFS determinations. The calculations also support the higher APTES affinity for Pb<sup>2+</sup> compared to Cd<sup>2+</sup>. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas Centro de Investigaciones Ópticas Centro de Investigación y Desarrollo en Fermentaciones Industriales