Hg sorption by Fe3O4/SiO2 core-shell nanoparticles functionalized with dithiocarbamate: Determining Hg coordination with a combined experimental and ab-initio approach

Nanoparticles functionalized with dithiocarbamate groups are well known for their high uptake efficiency of Hg(II) from water but where and how Hg coordinates is still an open question. In the present work, Perturbed Angular Correlations spectroscopy was combined with Density Functional Theory modelling to answer that question. Measuring the electric field gradient and comparing it with its calculated counterpart allows to determine the most probable local environment of Hg and its coordination, both for dithiocarbamate functionalized nanoparticles and for silica coated magnetite nanoparticles. The calculated bonding energy also answers why dithiocarbamate functionalized nanoparticles present such a high sorption efficiency. • The correlation between the measured and calculated EFG discriminates the Hg coordination. • The symbiosis of PAC and DFT unveiled the Hg coordination on DTC and Silica nanoparticles. • The calculated bonding energy correctly predicts the Hg sorption efficiency by the nanoparticles. • The calculated bonding energy justifies why DTC nanoparticles present the highest sorption efficiency.