Highly ordered pure and indium-incorporated MCM-41 mesoporous adsorbents: synthesis, characterization and evaluation for dye removal

Abstract

Highly ordered pure MCM-41 and In-MCM-41 mesoporous adsorbents (with Si/In = 95 (IM0.05) and Si/In = 90 (IM0.1)) were synthesized using the hydrothermal-assisted method. The structural, morphological and texture characteristics were investigated by XRD, N2 adsorption–desorption, SEM-EDX, TEM, diffuse reflectance (DR) and FTIR. The broadening XRD diffraction peaks as well as the shifts to higher and lower 2-theta in IM0.05 and IM0.1, respectively, confirmed the incorporation of indium atoms in the MCM-41 structure. SEM-EXD and TEM images showed that pure MCM-41 and IM0.05 preserve a highly long-range well-ordered hexagonal pore structure, on the other hand, high loading of indium (IM0.1) resulted in partially irregular pore-ordering and morphological defects related to a partial dissolution of MCM-41 structure. The infrared spectra of In-incorporated samples showed a decrease in the transmittance intensity of MCM-41 characteristic peaks with little shifts relative to the pure MCM-41 sample. The potential of pure MCM-41 and In-MCM-41 samples for adsorption of dyes was preliminarily investigated. The removal efficiency of both methylene blue and basic yellow-28 (BY28) was enhanced by the incorporation of indium in the MCM-41. The adsorption equilibrium data of BY28 dye on pure, IM0.05 and IM0.1 samples fitted well with Langmuir adsorption model with adsorption capacity of 123.46, 156.99 and 158.48 mg g−1 respectively. The calculated free adsorption energy obtained from D–R isotherm was found to be 26.7 kJ mol−1 referring to that the adsorption of BY28 on IM0.05 adsorbent is chemical. The adsorption kinetic of BY28 on IM0.05 sample followed the pseudo-second-order model. The adsorption experiments revealed that the prepared samples can be used as effective adsorbents for the removal of dyes in aqueous solutions with good recovery and recyclability. Graphical Abstract

Controlling Size Distribution of Silver Nanoparticles using Natural Reducing Agents in MCM‐41@Ag

“…As a general trend, there is a broadening of the diffraction peaks accompanied by shifts to higher or lower 2theta degrees, accompanied by shifts to higher or lower 2theta degrees. In this broadening, the loss of some characteristic peaks or the decrease of their intensity is a distinctive indication of the incorporation of metals into the silica structure [44] . This could be consistent with the values reported by Casas‐ Orozco et al.…”

“…In this broadening, the loss of some characteristic peaks or the decrease of their intensity is a distinctive indication of the incorporation of metals into the silica structure. [44] This could be consistent with the values reported by Casas-Orozco et al. [45] , and Gonzalez-Vargas et al, [46] who demonstrated that high dispersion of metal oxide in the silica matrix, results in the reduction of its bandgap.…”

Functionalized MCM-41 based recyclable catalyst for the epoxidation of alkenes using tert-BuOOH

“…The diffractogram of pure MCM-41 contain a strong peak ranging from 2ϴ= 2-3̊ corresponding to 100 planes with 2 weaker reflections at 4.4 (110) and 4.9 (200) planes, respectively. Appearance of these peaks confirmed the synthesis of highly ordered hexagonal mesostructure [45].After modification with organic moieties, the sharp reflection of 100 plane converted into broad peak with lower intensity meanwhile the 110 and 200 peaks to be weakened and consequently disappeared, indicating reduction in the long range-ordering mesostructure of MCM-41 channel [46]. Moreover, the existence of characteristic diffraction 100 in all the samples prove that MCM-41 still hold the hexagonal mesoporous structure even after grafting with metal complex.…”

“…Schiff base ligand (E)-2-((pyridin-4-ylmethylene)amino)phenol (PAL) was synthesized with the help of literature [44] and characterized with the help of NMR spectroscopy ( 1 H and 13 C)…”

Petroleum sludge ash-derived MCM-41-silver nanocomposites for enhanced photocatalysis and antimicrobial effect in water treatment

“…This successful surface dispersion aligns with the loading process and hints at a potential interaction between the Ag NPs and the MCM-41 surface. 49…”