Iodine speciation in deep eutectic solvents

Abstract

Iodine has been shown to act as a good electrocatalyst for metal digestion in deep eutectic solvents (DESs) but little is known about its speciation or reactivity in these high...

Tailoring lixiviant properties to optimise selectivity in E-waste recycling

“…Previous work has shown that iodine forms I 2 Cl − and I 3 − complexes in EG : ChCl with no additional water. 27 The presence of water or different ethylene glycol content may affect the formation of these species, as the solubility of iodine in ethylene glycol is 0.28 mol dm −3 , whereas the solubility in water is only 1.32 × 10 −3 mol dm −3 when no additional complexing agents are present. 43 Therefore, extended X-ray absorption fine structure (EXAFS) spectroscopy was carried at the iodine K-edge out on samples containing nominally 0.1 mol kg −1 iodine, with the DES containing a range of water contents up to 20 wt%, and also for four different molar ratios of EG : ChCl.…”

“…26 It has recently been determined that the HBD plays a critical role for the species of iodine that are formed in DES media, with three general speciation types observed: mixed I 2 Cl − and I 3 − , mixed I 2 and I 3 − , and I 3 − alone. 27 The amount of I 2 Cl − present was linked to the activity of the chloride anion, with high chloride activity resulting in higher amounts of I 2 Cl − . The chloride activity itself is related to the strength of the interactions between chloride and the HBD used.…”

A novel method for extracting metals from asteroids using non-aqueous deep eutectic solvents

“…In the case of iodine, it has been reported that both [I 2 Cl] − and [I 3 ] − are stable in ChCl: 2EG eutectic mixture (distribution between complexes tending to change as function of water addition) 81 , 82 , suggesting that both species should be able to oxidise iron according to Eqs. ( 7 , 8 ).…”

A toolbox for improved recycling of critical metals and materials in low-carbon technologies

“…111 They also have inherently high concentrations of ligands, permitting the chemical oxidation of noble metals such as gold, [112][113][114] or palladium. 115 Alternatively, the ionic environment can stabilise oxidising species such as iodine 116 or bromine 117 without the need for additional anions that would be required in aqueous media.…”