Modulated synthesis of thiol-functionalized fcu and hcp UiO-66(Zr) for the removal of silver(i) ions from water

Abstract

Mercaptoacetate modulation represents an easy way of introducing thiol groups into UiO-MOFs for enhanced uptake of Ag+ from aqueous solutions.

A caveat on the effect of modulators in the synthesis of the aluminum furandicarboxylate metal‐organic framework MIL‐160

“…Whereas, in the modulation of UiO-66 modulator equivalents up to 100 are often used. [20,25] Thus, direct comparison between modulation reactions for Al-based and Zr-based MOFs do not seem appropriate. The difference in modulator amount may be seen as a manifestation of the different lability/inertness of Al 3 + versus Zr 4 + (cf.…”

“…The ratio of modulator to linker in this work is below 2, due to side‐product formation etc. Whereas, in the modulation of UiO‐66 modulator equivalents up to 100 are often used [20,25] . Thus, direct comparison between modulation reactions for Al‐based and Zr‐based MOFs do not seem appropriate.…”

“…Moll et al . found that the use of very high amounts of mercaptoacetic acid in the synthesis of UiO‐66 leads to a phase change from face‐centered cubic, fcu to hexagonal close‐packed, hcp phase with a different framework structure [20] …”

“…[13] For applications like ethanol dehydration, [14] or the isosteric heat of adsorption of water [15] it can be necessary to tailor the characteristics of MOFs with respect to morphology, crystal size, porosity and defects, [16][17][18] e. g., through the use of modulators in their synthesis. [19,20] The kinetics of the framework formation can be influenced by modulating ligands which bind to the metal ion or cluster with a weaker binding energy than the linker. Thereby, the modulator competes with the linker and, for example, slows the crystal growth process or can in part remain in the MOF and induces linker defects.…”

“…MOFs are designable in their properties [5] in many different dimensions, which leads to a still rising scientific and commercial interest in promising applications, such as useful heat transformation, [6–8] catalysis, [9] gas and liquid separation, [10,11] natural gas [12] and methane storage [13] . For applications like ethanol dehydration, [14] or the isosteric heat of adsorption of water [15] it can be necessary to tailor the characteristics of MOFs with respect to morphology, crystal size, porosity and defects, [16–18] e. g., through the use of modulators in their synthesis [19,20] …”