On the Intercalation of the Iodine–Iodide Couple on Layered Double Hydroxides with Different Particle Sizes

Molecular iodine was intercalated from nonaqueous solution into microsized ZnAl-layered double hydroxide (LDH) in the iodide form, generating the I3 –/I– redox couple into the interlayer region. Chloroform, ethanol, acetonitrile, or diethyl ether were used as solvents to dissolve the molecular iodine. The intercalation compounds were characterized by thermogravimetric analysis, X-ray powder diffraction, UV–vis spectroscopy, and scanning and transmission electron microscopy. The stability of iodine–solvent adducts and the iodine concentration affected the LDH iodine loading, and samples with I2/I– molar ratio ranging from 0.14 to 0.82 were prepared. Nanosized, well dispersible LDH, synthesized by the urea method in water–ethylene glycol media, were also prepared and successfully functionalized with the I3 –/I– redox couple applying the conditions optimized for the micrometric systems.