Amino-functionalized MCM-41 for the simultaneous electrochemical determination of trace lead and cadmium

Selective preconcentration separation of Hg(ii) and Cd(ii) from water, fish muscles, and cucumber samples using recycled aluminum adsorbents

“… 24 The bending vibrations of Al–O–Al groups were confirmed via the presence of a band in the range from 461 cm −1 to 465 cm −1 . 30 The bands that appeared at 1632 and 3424 cm −1 were assigned to the bending and stretching vibrations of OH groups, respectively. 29 New absorption bands were noticed for the BAA sorbent at 1641, 3000, and 3035 cm −1 , which refer to C N stretching, and C–H stretching vibrations of aliphatic and aromatic structures, respectively.…”

Methylation of 2-methylnaphthalene over metal-impregnated mesoporous MCM-41 for the synthesis of 2,6-triad dimethylnaphthalene isomers

“…There are hydroxyl groups on the surface as indicated with the broadband around 3440 cm -1 and the band around 1610 cm -1 are defined as the Si-OH deformational vibrations of adsorbed molecules [33,34]. The internal and external asymmetric stretching of Si-O-Si groups are observed at around 805 cm -1 and 1090 cm -1 with a corresponding shoulder at 1239 cm -1 and the band at 465 cm -1 attributed to symmetric stretching modes of tetrahedral Si-O-Si and M-O-Si (M; metal) bending modes [31,34,35,43,49,50]. As the adding metals on the zeolite, the absorption bands became stronger at 450-960 cm −1 , indicating the metals in the MCM-41 framework.…”

“…3.2°, and 5° before and after modification, corresponding to (100), (110), and (200) characteristic peaks of the amorphous mesoporous silica which suggesting that metal impregnation has insignificant effect on the structure of MCM-41 zeolite integrity[44,[46][47][48][49][50]. The wide-angle diffraction peaks at 2θ=35.5°, 38.6°, 48.8°, 53.3°, 58.1°, 61.5°, 65.6°, and 67.7° were attributed to Cu 2+ form on Cu/MCM-41 and Cu/Zr/MCM-41 catalysts[34,46,51].…”

Three-Dimensional (3D) Surface-Enhanced Raman Spectroscopy (SERS) Substrates: Fabrication and SERS Applications

“…13,15,16 The tuning of the porosity allows to control pore size and pore volume, and their surface can be chemically modified by different functional groups. 14,15 This physical and chemical flexibility allows to optimize the properties to immobilize metal NPs on their surface. 17 There have been prior reports of functionalized silica and polystyrene particles decorated with silver and Au NPs for SERS measurements.…”

“…Silica microspheres (SMPs) are excellent candidates for this purpose and have attracted great attention for their usage in drug delivery, 11 electrochemical sensors, 12,13 and catalysis. 14 The versatile synthesis of SMPs gives the flexibility to tailor their properties like size, shape, and porosity. 13,15,16 The tuning of the porosity allows to control pore size and pore volume, and their surface can be chemically modified by different functional groups.…”