Electronic and magnetic properties of the adsorption of As harmful species on zero-valent Fe surfaces, clusters and nanoparticules

ALFONSO TOBÓN, LESLIE L.; FUENTE, SILVIA; BRANDA, MARÍA M.

APPLIED SURFACE SCIENCE

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2019 vol. 465 p. 715 - 715

0169-4332

systematic theoretical study of the adsorption of H3AsO3 and H3AsO4 acids on Fe nanoparticles was carried out using the Density Functional Theory (DFT). Different sizes of zero-valent iron particles and also the two moststable surfaces of Fe, (1 1 1) and (1 1 0), were studied by characterizing the type of interaction present between the substrates and the adsorbates. Arsenic acid (H3AsO4) is spontaneously reduced in both extended surfaces ofiron, producing arsenious acid and oxidizing the metal surface. Arsenious acid (H3AsO3) completely decomposes into (AsOH)(OH)(OH) fragments on the smallest particles, Fe32 and Fe59, but also on the (1 1 1) surface.However, on greater particles (NP80 and NP113) and on the (1 1 0) surface, H3AsO3 retains its initial free configuration and is joined to the surface through both atoms, As and O. Large dispersion components of theadsorption energy were observed when the acids interact with the substrates without decomposition. From a Bader analysis of t