Synthesis of mesoporous silica-coated magnetic nanoparticles modified with 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole and its application as Cu(II) adsorbent from aqueous samples

Abstract

This study presents an alternative, rapid, and environment-friendly synthesis procedure of a magnetic core-shell mesoporous SBA-15 silica composite, its functionalization with 4-amino-3-hydrazino-5mercapto-1,2,4-triazole (Purpald), and its application in dispersive solid-phase microextraction (DSPME) for Cu(II) from water. The materials were characterized through magnetization measurements, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), Fourier transform infrared (FTIR), nuclear magnetic resonance (NMR) of 29 Si and 13 C, elemental analysis, and surface area measurements. FTIR and NMR analyses indicated the presence of the ligand on the functionalized material and that it was coupled through a C S bond. TEM images clearly show that the magnetite core particles were effectively coated with a silica shell. The material presented a surface area of 287.99 m 2 g −1 and an average pore diameter of approximately 15.1 nm. The material had its point of zero charge (PZC) determined (6.17) and its adsorption capacity was evaluated as a function of time, pH, and metal concentration. Dynamic adsorption equilibrium was reached in 120 min, and it had a good correlation with the pseudo-second-order kinetic model (r 2 = 0.9997). The maximum experimental adsorption capacity (0.0786 mmol g −1) and the value calculated by the linearized Langmuir model (0.0799 mmol g −1) are very approximate, indicating the formation of a monolayer over the material. Furthermore, the material proved to be very stable, because their adsorption capacity remained greater than 95% even after 10 cycles of adsorption/desorption. A high enrichment factor of 98.1-fold was observed, indicating that this material is suitable for the preconcentration of trace Cu(II) ions before analysis through flame atomic absorption spectrometry (FAAS).

Removal of Ni(II), Cu(II), and Zn(II) ions from aqueous solution using Tetraselmis sp. biomass modified with silica-coated magnetite nanoparticles

“…Optimum condition of adsorption process of Ni(II), Cu(II), and Zn(II) ions on MNPs that happened at pH 6 tends to be in line with the value of pH of zero point charge (pH ZPC ) determined by previous research [37,61] on the adsorbents based silica-magnetite nanoparticle and Fe 3 O 4 /cyclodextrin polymer nanocomposites with the value of pH ZPC 6.2 and 4.4, respectively. If medium pH above pH ZPC (pH > pH PZC ), the adsorbent surface will be negative charge caused by deprotonation of functional groups or adsorption of hydroxyl species.…”

β-Keto-enol Tethered Pyridine and Thiophene: Synthesis, Crystal Structure Determination and Its Organic Immobilization on Silica for Efficient Solid-Liquid Extraction of Heavy Metals

“…This efficiency is mainly due to the affinity of the ligand donor atoms towards this metal. 1-(Furan-2-yl) imine [19] 77.48 EDTA [35] 85.75 Pentane-1,2-dicarboxylic acid [36] 38.00 Schiff base tailed silatranes [37] 13.15 Stearic acid [38] 63.00 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole [39] 05.02…”

Application of Modified Green Algae Nannochloropsis sp. as Adsorbent in the Sequential Adsorption of Methylene Blue and Cu(II) Cations in Solution

“…In addition, a rising in the sorption rate capacity of the adsorbate is able to be carried out using magnetite particle coating techniques [31][32][33]. The adsorbent coating technique by particles of magnetite is safe for environment, since it does not produce side products that conceive contamination like suspended solids, besides that it also accelerates the process of isolating the adsorbate from the solution caused by the magnetic properties of the adsorbent [34][35][36][37][38]. By using the adsorbent coating technique using magnetite particles, we will get an adsorbent with a big adsorption rate and capacity to the adsorbate, so that the adsorption process becomes more efficient.…”