Facile Synthesis of Thiol‐functionalized Mesoporous Silica – Their Role for Heavy Metal Removal Efficiency

Abstract

A simple approach based on the covalent grafting of 3-mercaptopropyltrimethoxysilane groups onto the framework of two types of mesoporous silica C16 (surface area: 1568.72 m 2 /g; pore size: 3.07 nm) using hexadecyltrimethyl ammoniumbromide and C9 (surface area: 779.83 m 2 /g; pore size: 4.51 nm) using nonyltrimethyl ammoniumbromide as templates has been reported. Various techniques were employed to confirm the thiol functionalization. A considerable decline in the surface area, pore volume, and interestingly an enhancement in the pore size were observed for functionalized materials. The functionalized derivatives were able to bind quantitatively several folds Ag þ and Hg 2þ ions compared to that of unmodified mesoporous silica and a comparative study with earlier reports indicated that the mesoporous silica discussed in this present work showed superior adsorption behavior. Mercapto-functionalized mesoporous silica have not only exhibited an enhanced adsorption rate towards Ag þ and Hg 2þ but also demonstrated that the maximum adsorption capacity of Ag þ (C16 ¼ 0.73 mg/g; C16-SAn ¼ 192.31 mg/g; C16-SH ¼ 250.00 mg/g; C9 ¼ 0.66 mg/g; C9-SAn ¼ 181.82; C9-SH ¼ 185.85 mg/g) and Hg 2þ (C16 ¼ 0.40 mg/g; C16-SAn ¼ 114.94 mg/g; C16-SH ¼ 126.58 mg/g; C9 ¼ 0.31 mg/g; C9-SAn ¼ 108.70; C9-SH ¼ 112.36 mg/g) is hundred times higher than that of unmodified mesoporous silica. Thus, it is evident that these thiol-functionalized mesoporous silica can be promising adsorbents for the treatment of Hg 2þ and Ag þ contaminants in aqueous solution.Abbreviations: BET, Brunauer-Emmett-Teller; FT-IR, Fourier transform infrared; HDTMDB, hexadecyltrimethyl ammoniumbromide; MPTMS, 3-mercaptopropyltrimethoxysilane; NTMAB, nonyltrimethyl ammoniumbromide; SEM, scanning electron microscopy 775

Highly promoted removal of Hg(ii) with magnetic CoFe2O4@SiO2 core–shell nanoparticles modified by thiol groups

“…Aer the introduction of mercapto groups by MPTMS, the BET value returned to the original value, which may be due to the existence of large amount of organic mercapto groups graed into CoFe 2 O 4 @SiO 2 mesopores. 27 On one hand, it shows the successful graing of -SH; on the other hand, it indicates that the BET value was not the main factor affecting the adsorption performance of CoFe 2 O 4 @SiO 2 -SH.…”

Silica based inorganic–organic hybrid materials for the adsorptive removal of chromium

“…Moreover, the calculated value of R L is also in the required range of 0 < R L < 1 for SG-AEMH (0.13) and MS-PEI (0.07), signifying a favourable adsorption of Cr(VI). 49,[69][70][71] Adsorption kinetics…”

Synthesis and Characterizations of Titanium Tungstosilicate and Tungstophosphate Mesoporous Materials

“…As an example, Lee et al [22] reported the adsorption of Pb(II) and Cu(II) metal ions on mesoporous silica modified with organic amine and thiol functional groups and results reveal that the thiol-functionalized mesoporous silica adsorbents exhibit enhanced adsorption affinity for Pb 2+ than the amino-mesoporous silica. Moreover, other studies reported an excellent Hg removal efficiency on thiolated mesoporous silica compared to the aminated ones [23,25].…”