Post-functionalization of UiO-66-NH2 by 2,5-Dimercapto-1,3,4-thiadiazole for the high efficient removal of Hg(II) in water

A POSS‐Phosphazene Based Porous Material for Adsorption of Metal Ions from Water

“…Ac omparatives tudy allows to detect Si-O-Si (1100 cm À1 )a nd PÀN( 1200 cm À1 )s egments arising from POSS and cyclo-phosphazeneu nits, respectively in the polymer.T he broadening of these peaks suggests the formation of cross-linked structure.T he band at 3440 cm À1 is attributedt o SiÀOH fragments due to partial cleavage of Si-O-Si bonds of the cage POSS during the Heck reaction. [57,58] In solid state 29 Si NMR spectrum (Figure 2a), the signals at À69.2 and À76.8 ppm are assigned to T 2 andT 3 units (T n is C-Si(OSi) n (OH) 3Àn ), and signals at À99.0 and À107.2 ppm suggest the formation of Q 3 and Q 4 units (Q n is Si(OSi) n (OH) 4Àn )d ue to partial cleavage of the POSS cyclic structure (Figure2b). Similar cleavage of siloxaneb onds of POSS units due to presence of bases, such as triethylamine or NaHCO 3 during Heck reaction was reported previously.…”

“…In the past, extensive studies have been reported to unravel the scopeo fs uch functional materials as activated porous carbon, [5] zeolites, [6] silica particles, [7][8][9][10][11][12][13] graphene oxide, [14,15] metals or metal oxides, [16,17] natural minerals [18][19][20] etc. as adsorbents for remediationo fm etal ions from water.T he search for new and efficient adsorbentsh as prompted the design and synthesis of functional polymers, [21][22][23][24][25][26][27] metal organic frameworks, [28][29][30] polymeric composites [31][32][33] and biohybrids. [34] Nev-ertheless, the problem of low adsorption capacity of these materials stillr emains ac hallenge due to lack of synthetic methods which favor modulations in the physicalp roperties and surfacec hemistry.I tm eanst hat except high surface area the designeda dsorbent should possess functional electron-rich groups on thes urface, whichw ill have strongi nteractionw ith metal ions.…”

Adsorption Processing for the Removal of Toxic Hg(II) from Liquid Effluents: Advances in the 2019 Year

“…Moreover, in the case of manuscripts which presented data about the continuous usage (cycles) of the given adsorbents (a remarkable point seeing the previous percentage), it is shown that in the majority of the cases, and against it is stated by the respective authors, the adsorbent lost a significant capacity of its Hg(II) uptake with respect to the initial one. 3.34 Ui-66-NH 2 post-funcionalization [24] 0.03 Magnetic hydrogel of lignin [74] The distribution is based in the Institution-Country of the corresponding author e-mail. Others included: Brazil, Colombia, France, Iraq, Kazakhstan, Mexico, New Zealand, Philippines, Portugal, Russia, Spain, United Arab Emirates.…”

“…Cysteine modified cellulose nanocrystal [52] 0.05 Funcionalized carbon [56] 3.34 Ui-66-NH2 post-funcionalization [24] 0.03 Magnetic hydrogel of lignin [74] Practically all of the manuscripts considered the pH, of the Hg(II)-bearing aqueous solution, as one of the variables to be investigated, and most of the manuscripts considered the 1-8 pH range for their investigations. However, and according with the stability diagrams generated from the authors of this review ( Figure 6) by MEDUSA Program [120], in nitrate medium and from approximately at a pH of 4, the predominant species is Hg(OH)2 which does not solubilize in the medium; in the case of chloride medium this pH value shifted until the value of 5.5.…”

“…The adsorption properties were repeated at least for four cycles. An MOFs adsorbent was prepared by post-functionalization of UiO-66-NH2 with 2,5-dimercapto-1,3,4-thiadiazole and used to remove the Hg(II) in water [24]. At a pH value of 3, the maximum adsorption capacity was 3.34 mmol/g.…”