Synthesis and Characterization of New Schiff Base/Thiol-Functionalized Mesoporous Silica: An Efficient Sorbent for the Removal of Pb(II) from Aqueous Solutions

Abstract

A new type of silica hybrid material functionalized with Schiff base-propyl-thiol and propyl-thiol groups (adsorbents 1 and 2, respectively) was synthesized using a co-condensation method. The synthesized materials and their starting materials were successfully characterized using a variety of techniques such as Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), nitrogen adsorption–desorption isotherms, the Brunauer–Emmett–Teller (BET) surface area calculation method, the Barrett, Joyner, and Halenda (BJH) pore size calculation method, thermogravimetry analysis (TGA), and 1H and 13C nuclear magnetic resonance (NMR) spectra. The results indicate that the new material (adsorbent 1) has a large surface and possesses different functional groups (-SH, -OH, -C=O and –N=C). The newly synthesized hybrid materials (1 and 2) were investigated as potential adsorbents for removal of toxic heavy metals, such as Pb(II) from aqueous solutions. The adsorption results show that materials 1 and 2 have different sorption properties and were found to be effective adsorbents for Pb(II) removal from aqueous solutions. In addition, compound 1 exhibited a higher adsorption capacity for Pb(II) compared to compound 2. The results showed that the optimum pH for Pb(II) sorption was 6.5. Contact time was observed to occur after 30 min for 25 mg L−1 Pb(II) concentration and adsorbent dose of 0.4 g L−1 at 25 °C.

Alkaline hydrogel electrolyte from biosourced chitosan to enhance the rate capability and energy density of carbon-based supercapacitors

“…First, it can be observed that the Schiff base and O-H stretching groups located at B3400 cm À1 overlap and increase with the ageing time. 51 This can have the following origins: (i) the presence of glyoxylic acid in water, in which the carbonyl converts to a geminal diol (two hydroxyl O-H functional groups bound to the same carbon) 52 and (ii) the reaction of chitosan and glyoxylic acid leading to a Schiff base 53 (imines with a characteristic CQN bonds) formation, which is accompanied by the formation of H 2 O molecules. According to the literature, the Schiff base is present between 3200 and 3400 cm À1 .…”

Rapid adsorption of some heavy metals using extracted chitosan anchored with new aldehyde to form a schiff base

“…It was reported that chitosan Schiff bases have excellent chelation ability with heavy metal ions, because it can act as a good binding site for many transition metals and therefore can form stable coordination complexes [12,13]. In azomethine derivatives, the C = N linkage is essential for biological activity; several azomethines were reported to possess remarkable antibacterial, antifungal, anticancer, and diuretic activities.…”

Development of al‐doped MgMn2O4‐based cathode materials for magnesium ion cells

“…The particle size, pore size and porosity percentage were determined by using ImageJ software from imaging FESEM results. [28][29][30] F I G U R E 4 Field emission scanning electron microscopy (FESEM) images of (A) MMO, (B) MMAO1, (C) MMAO2, and (D) MMAO3.…”

“…Figure9represented the CV curves for un-doped and Al-doped at scan rate of 50 mV s −1 with potential window of 0 -3 V for 5 cycles in 1 M MgTf 2 electrolyte. Ahmed et al and Venkataraman et al proved that the technique of three electrodes for CV setup using liquid electrolyte containing fluoride element shown the promising good result although they run with high scan rate of 50 mV s −1 and 100 mV s −1 in room temperature 29,30. CV curve belongs to MMO sample and represents the oxidation and reduction curves with overlapping cycles.…”