Experimental and DFT studies for selective separation of Sb(iii) and Sb(v) from mixtures with Zr(iv)/Co(ii) using thiourea grafted polystyrene adsorbent

Abstract

Graphical AbstractThe 'S' atom of thiourea functionalized polystyrene adsorbent exhibited very strong interaction with excellent separation of antimony(III and V) ions in presence of large concentration of cobalt and zirconium ions. Abstract 1 A thiourea functionalized polystyrene adsorbent (TPS-DVB) is theoretically and 2 experimentally investigated for selective sorption of antimony from acidic aqueous mixtures 3 with CoCl 2 and ZrOCl 2 . The optimal uptake of 35.6 and 24.2 mg.g -1 , respectively, was obtained 4 for antimony(III) and antimony(V), at pH 1. The isotherm data could be well explained by the 5 Langmuir model and the adsorption kinetics was successfully fitted in the pseudo first-order 6 kinetics. Very high separation factors of 1129 and 918 were achieved for the Sb(III)/Co(II) and 7 Sb(V)/Co(II) mixtures, respectively. The adsorption of Sb(III) and Sb(V) ions onto the TPS-8 DVB adsorbent was explored using the Density Functional Theory (DFT). These theoretical 9 studies of metal coordination with the sulfur atom in the isothiourea group of the adsorbent 10 showed stronger interaction of Sb(III) and Sb(V) ions over Co(II) and ZrO(II) ions. The 11 inclusion of solvation model in the theoretical calculations improved the agreement between the 12 experimental and the calculated metal-sulphur bond distances.13 14

Molecular design of a novel ligand for Menshutkin complexation of Bi(iii) from aqueous acidic copper sulfate electrolyte solutions and experimental investigations

“…Moreover, the more reactive nucleophile is supposed to have a lower value of u while the opposite is affirmed for an electrophile. 45 In the present study, the ligand exhibits lower c and u values as compared to the metal-anion species (Table 2). These values signify that the phen-arene ligand is nucleophilic and thus interacts well with the metal ions forming complexes.…”

“…The optimized geometries of the individual complexes of bismuth, antimony, arsenic and copper ions, surrounded with counterions (HSO 45 of the complexes, estimated by using (eqn (4)), are given in Table 3.…”

“…Hence for quantitative uptake of the metal by the adsorbent, the adsorbent concentration needs to be optimized. 66 Therefore, the quantitative sorption of Bi(III) from the acidic solution was studied by varying the adsorbent concentration between 0.1 and 0.5 g. The metal ion uptake was estimated as (% R) (eqn ( 5)) 45 and adsorption capacity per unit weight of adsorbent, Q av , given by eqn (6), 45 respectively.…”