Vibration spectroscopic evidence for different interactive modes of iodide on gibbsite in humic acid mediation

Determination of the fate of iodide and associated species is an important scientific question from environmental and nuclear energy perspectives. The chemical kinetics of iodide adsorption on gibbsite was examined in the presence of humic acids (HA). The iodide retention was highest in HA-coated gibbsite (ΓI 15.5 μmol m2−; pH 6.50) and lowest in HA-iodide-gibbsite ternary systems (ΓI 9.56 μmol m2−; pH 6.50). Both inter- and intralayer OH groups have distinguishable IR manifestations for iodide retention on gibbsite. In HA-coated gibbsite, the enhanced iodide retention was ascribed to direct bonding with surface Al-sites.