Cu²⁺ grafting in Th-metal organic framework and its effect on iodine adsorption

Metal organic frameworks (MOFs) have emerged as promising materials for gas adsorption mechanism due to their relatively high specific surface area (SSA), tailorable pore architecture and tunable chemistry. In this direction, UiO-66 type MOF are found to be relatively more stable. XRD patterns of synthesized MOFs and are in good agreement with the literature, confirming the formation of MOFs. XRF studies of Th-BiPy/Cu MOF has shown that the relative concentration of Th:Cu is near to 1:1 which signifies that the Cu²⁺ ion has grafted in all the bipyridyl moieties of the parent MOF. The calculated BET surface area and pore volume of Th-BiPy MOF was found to be 409.32 m²/g and 0.23 cm³/g respectively. From the Iodine adsorption studies, it can be seen that the iodine adsorption capacity of metal grafted MOF has decreased to around 1/3 of the parent MOF which can be attributed to the fact that Cu²⁺ ion has also occupied the pores of host MOF which results in lesser surface area for the guest Iodine atoms