Synthesis of novel adsorbent based on tetrasulfide-functionalized fibrous silica KCC-1 for removal of Hg(II) cations

AbstractHg(II) has been identified to be one of the extremely toxic heavy metals because of its hazardous effects and this fact that it is even more hazardous to animals than other pollutants such as Ag, Au, Cd, Ni, Pb, Co, Cu, and Zn. Accordingly, for the first time, tetrasulfide-functionalized fibrous silica KCC-1 (TS-KCC-1) spheres were synthesized by a facile, conventional ultrasonic-assisted, sol–gel-hydrothermal preparation approach to adsorb Hg(II) from aqueous solution. Tetrasulfide groups (–S–S–S–S–) were chosen as binding sites due to the strong and effective interaction of mercury ions (Hg(II)) with sulfur atoms. Hg(II) uptake onto TS-KCC-1 in a batch system has been carried out. Isotherm and kinetic results showed a very agreed agreement with Langmuir and pseudo-first-order models, respectively, with a Langmuir maximum uptake capacity of 132.55 mg g–1 (volume of the solution = 20.0 mL; adsorbent dose = 5.0 mg; pH = 5.0; temperature: 198 K; contact time = 40 min; shaking speed = 180 rpm). TS-KCC-1was shown to be a promising functional nanoporous material for the uptake of Hg(II) cations from aqueous media. To the best of our knowledge, there has been no report on the uptake of toxic Hg(II) cations by tetrasulfide-functionalized KCC-1 prepared by a conventional ultrasonic-assisted sol–gel-hydrothermal synthesis method.

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Solvent-Free Powder Synthesis and MOF-CVD Thin Films of the Mesoporous Metal-Organic Framework MAF-6

10.26434/chemrxiv.9860891.v1 ◽

2019 ◽

Author(s):

Timothée Stassin ◽

Ivo Stassen ◽

Joao Marreiros ◽

Alexander John Cruz ◽

Rhea Verbeke ◽

...

Keyword(s):

Vapor Phase ◽

Metal Organic Framework ◽

Chemical Vapor ◽

Uptake Capacity ◽

Powder Synthesis ◽

Crystalline Films ◽

Metal Organic ◽

Mesoporous Metal ◽

First Time ◽

Organic Framework

A simple solvent- and catalyst-free method is presented for the synthesis of the mesoporous metal-organic framework (MOF) MAF-6 (RHO-Zn(eIm)2) based on the reaction of ZnO with 2-ethylimidazole vapor at temperatures ≤ 100 °C. By translating this method to a chemical vapor deposition (CVD) protocol, mesoporous crystalline films could be deposited for the first time entirely from the vapor phase. A combination of PALS and Kr physisorption measurements confirmed the porosity of these MOF-CVD films and the size of the MAF-6 supercages (diam. ~2 nm), in close agreement with powder data and calculations. MAF-6 powders and films were further characterized by XRD, TGA, SEM, FTIR, PDF and EXAFS. The exceptional uptake capacity of the mesoporous MAF-6 in comparison to the microporous ZIF-8 is demonstrated by vapor-phase loading of a molecule larger than the ZIF-8 windows.

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Green Synthesis and Spectroscopic Studies of Ag-rGO Nanocomposites for Highly Selective Mercury (II) Sensing

Nanoscience &Nanotechnology-Asia ◽

10.2174/2210681207666170705143629 ◽

2018 ◽

Vol 9 (1) ◽

pp. 101-108 ◽

Cited By ~ 1

Author(s):

Shubhangi J. Mane-Gavade ◽

Sandip R. Sabale ◽

Xiao-Ying Yu ◽

Gurunath H. Nikam ◽

Bhaskar V. Tamhankar

Keyword(s):

Green Synthesis ◽

Color Change ◽

Limit Of Detection ◽

Aqueous Media ◽

Suitable Condition ◽

Cost Effective ◽

Spectroscopic Studies ◽

Calibration Plot ◽

First Time

Introduction: Herein we report the green synthesis and characterization of silverreduced graphene oxide nanocomposites (Ag-rGO) using Acacia nilotica gum for the first time. Experimental: We demonstrate the Hg2+ ions sensing ability of the Ag-rGO nanocomposites form aqueous medium. The developed colorimetric sensor method is simple, fast and selective for the detection of Hg2+ ions in aqueous media in presence of other associated ions. A significant color change was noticed with naked eye upon Hg2+ addition. The color change was not observed for cations including Sr2+, Ni2+, Cd2+, Pb2+, Mg2+, Ca2+, Fe2+, Ba2+ and Mn2+indicating that only Hg2+ shows a strong interaction with Ag-rGO nanocomposites. Under the most suitable condition, the calibration plot (A0-A) against concentration of Hg2+ was linear in the range of 0.1-1.0 ppm with a correlation coefficient (R2) value 0.9998. Results & Conclusion The concentration of Hg2+ was quantitatively determined with the Limit of Detection (LOD) of 0.85 ppm. Also, this method shows excellent selectivity towards Hg2+ over nine other cations tested. Moreover, the method offers a new cost effective, rapid and simple approach for the detection of Hg2+ in water samples.

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Correction: Poly(adenine)-mediated DNA-functionalized gold nanoparticles for sensitive detection of mercury ions in aqueous media

RSC Advances ◽

10.1039/d1ra90129j ◽

2021 ◽

Vol 11 (37) ◽

pp. 22691-22691

Author(s):

Jinjin Yin ◽

Jiuchao Wang ◽

Xiyue Yang ◽

Tao Wu ◽

Huashan Wang ◽

...

Keyword(s):

Gold Nanoparticles ◽

Aqueous Media ◽

Sensitive Detection ◽

Mercury Ions ◽

Functionalized Gold Nanoparticles

Correction for ‘Poly(adenine)-mediated DNA-functionalized gold nanoparticles for sensitive detection of mercury ions in aqueous media’ by Jinjin Yin et al., RSC Adv., 2019, 9, 18728–18733, DOI: 10.1039/C9RA03041G.

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Eco-Friendly Colloidal Aqueous Sol-Gel Process for TiO2 Synthesis: The Peptization Method to Obtain Crystalline and Photoactive Materials at Low Temperature

Catalysts ◽

10.3390/catal11070768 ◽

2021 ◽

Vol 11 (7) ◽

pp. 768

Author(s):

Julien G. Mahy ◽

Louise Lejeune ◽

Tommy Haynes ◽

Stéphanie D. Lambert ◽

Raphael Henrique Marques Marcilli ◽

...

Keyword(s):

Organic Pollutant ◽

Sol Gel ◽

Synthesis Method ◽

Specific Treatment ◽

High Specific Surface Area ◽

Crystalline Phases ◽

Tio2 Photocatalysts ◽

Tio2 Anatase ◽

Synthesis Parameters ◽

Calcination Step

This work reviews an eco-friendly process for producing TiO2 via colloidal aqueous sol–gel synthesis, resulting in crystalline materials without a calcination step. Three types of colloidal aqueous TiO2 are reviewed: the as-synthesized type obtained directly after synthesis, without any specific treatment; the calcined, obtained after a subsequent calcination step; and the hydrothermal, obtained after a specific autoclave treatment. This eco-friendly process is based on the hydrolysis of a Ti precursor in excess of water, followed by the peptization of the precipitated TiO2. Compared to classical TiO2 synthesis, this method results in crystalline TiO2 nanoparticles without any thermal treatment and uses only small amounts of organic chemicals. Depending on the synthesis parameters, the three crystalline phases of TiO2 (anatase, brookite, and rutile) can be obtained. The morphology of the nanoparticles can also be tailored by the synthesis parameters. The most important parameter is the peptizing agent. Indeed, depending on its acidic or basic character and also on its amount, it can modulate the crystallinity and morphology of TiO2. Colloidal aqueous TiO2 photocatalysts are mainly being used in various photocatalytic reactions for organic pollutant degradation. The as-synthesized materials seem to have equivalent photocatalytic efficiency to the photocatalysts post-treated with thermal treatments and the commercial Evonik Aeroxide P25, which is produced by a high-temperature process. Indeed, as-prepared, the TiO2 photocatalysts present a high specific surface area and crystalline phases. Emerging applications are also referenced, such as elaborating catalysts for fuel cells, nanocomposite drug delivery systems, or the inkjet printing of microstructures. Only a few works have explored these new properties, giving a lot of potential avenues for studying this eco-friendly TiO2 synthesis method for innovative implementations.

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Mechanochemical Synthesis and Nitrogenation of the Nd1.1Fe10CoTi Alloy for Permanent Magnet

Molecules ◽

10.3390/molecules26133854 ◽

2021 ◽

Vol 26 (13) ◽

pp. 3854

Author(s):

Hugo Martínez Sánchez ◽

George Hadjipanayis ◽

Germán Antonio Pérez Alcázar ◽

Ligia Edith Zamora Alfonso ◽

Juan Sebastián Trujillo Hernández

Keyword(s):

Mechanochemical Synthesis ◽

Applied Field ◽

Volume Fraction ◽

Synthesis Method ◽

High Energy ◽

Direction Parallel ◽

Best Value ◽

Heat Treated ◽

Bcc Phase ◽

First Time

In this work, the mechanochemical synthesis method was used for the first time to produce powders of the nanocrystalline Nd1.1Fe10CoTi compound from Nd2O3, Fe2O3, Co and TiO2. High-energy-milled powders were heat treated at 1000 °C for 10 min to obtain the ThMn12-type structure. Volume fraction of the 1:12 phase was found to be as high as 95.7% with 4.3% of a bcc phase also present. The nitrogenation process of the sample was carried out at 350 °C during 3, 6, 9 and 12 h using a static pressure of 80 kPa of N2. The magnetic properties Mr, µ0Hc, and (BH)max were enhanced after nitrogenation, despite finding some residual nitrogen-free 1:12 phase. The magnetic values of a nitrogenated sample after 3 h were Mr = 75 Am2 kg–1, µ0Hc = 0.500 T and (BH)max = 58 kJ·m–3. Samples were aligned under an applied field of 2 T after washing and were measured in a direction parallel to the applied field. The best value of (BH)max~114 kJ·m–3 was obtained for 3 h and the highest µ0Hc = 0.518 T for 6 h nitrogenation. SEM characterization revealed that the particles have a mean particle size around 360 nm and a rounded shape.

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Aqueous Sol-Gel Synthesis of Different Iron Ferrites: From 3D to 2D

Materials ◽

10.3390/ma14061554 ◽

2021 ◽

Vol 14 (6) ◽

pp. 1554

Author(s):

Justinas Januskevicius ◽

Zivile Stankeviciute ◽

Dalis Baltrunas ◽

Kęstutis Mažeika ◽

Aldona Beganskiene ◽

...

Keyword(s):

Magnetic Measurements ◽

Substrate Surface ◽

Sol Gel ◽

Synthesis Method ◽

Xrd Analysis ◽

Dip Coating ◽

Yttrium Iron ◽

Iron Garnet ◽

Dip Coating Technique ◽

Sol Gel Synthesis

In this study, an aqueous sol-gel synthesis method and subsequent dip-coating technique were applied for the preparation of yttrium iron garnet (YIG), yttrium iron perovskite (YIP), and terbium iron perovskite (TIP) bulk and thin films. The monophasic highly crystalline different iron ferrite powders have been synthesized using this simple aqueous sol-gel process displaying the suitability of the method. In the next step, the same sol-gel solution was used for the fabrication of coatings on monocrystalline silicon (100) using a dip-coating procedure. This resulted, likely due to substrate surface influence, in all coatings having mixed phases of both garnet and perovskite. Thermogravimetric (TG) analysis of the precursor gels was carried out. All the samples were investigated by X-ray powder diffraction (XRD) analysis. The coatings were also investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM) and Mössbauer spectroscopy. Magnetic measurements were also carried out.

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How Can the Introduction of Zr4+ Ions into TiO2 Nanomaterial Impact the DSSC Photoconversion Efficiency? A Comprehensive Theoretical and Experimental Consideration

Materials ◽

10.3390/ma14112955 ◽

2021 ◽

Vol 14 (11) ◽

pp. 2955

Author(s):

Aleksandra Bartkowiak ◽

Oleksandr Korolevych ◽

Gian Luca Chiarello ◽

Malgorzata Makowska-Janusik ◽

Maciej Zalas

Keyword(s):

Density Functional ◽

Sol Gel ◽

Dye Sensitized Solar Cells ◽

Positive Influence ◽

Photoconversion Efficiency ◽

Doped Tio2 ◽

Computational Calculations ◽

Tio2 Nanomaterials ◽

First Time ◽

Sensitized Solar Cells

A series of pure and doped TiO2 nanomaterials with different Zr4+ ions content have been synthesized by the simple sol-gel method. Both types of materials (nanopowders and nanofilms scratched off of the working electrode’s surface) have been characterized in detail by XRD, TEM, and Raman techniques. Inserting dopant ions into the TiO2 structure has resulted in inhibition of crystal growth and prevention of phase transformation. The role of Zr4+ ions in this process was explained by performing computer simulations. The three structures such as pure anatase, Zr-doped TiO2, and tetragonal ZrO2 have been investigated using density functional theory extended by Hubbard correction. The computational calculations correlate well with experimental results. Formation of defects and broadening of energy bandgap in defected Zr-doped materials have been confirmed. It turned out that the oxygen vacancies with substituting Zr4+ ions in TiO2 structure have a positive influence on the performance of dye-sensitized solar cells. The overall photoconversion efficiency enhancement up to 8.63% by introducing 3.7% Zr4+ ions into the TiO2 has been confirmed by I-V curves, EIS, and IPCE measurements. Such efficiency of DSSC utilizing the working electrode made by Zr4+ ions substituted into TiO2 material lattice has been for the first time reported.

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Sol-Gel Synthesis of the Double Perovskite Sr2FeMoO6 by Microwave Technique

Materials ◽

10.3390/ma14143876 ◽

2021 ◽

Vol 14 (14) ◽

pp. 3876

Author(s):

Jesús Valdés ◽

Daniel Reséndiz ◽

Ángeles Cuán ◽

Rufino Nava ◽

Bertha Aguilar ◽

...

Keyword(s):

Particle Size ◽

Hydrothermal Synthesis ◽

Microwave Radiation ◽

Structural Characteristics ◽

Sol Gel ◽

Synthesis Method ◽

Double Perovskite ◽

Synthesis Methods ◽

X Ray ◽

Sol Gel Synthesis

The effect of microwave radiation on the hydrothermal synthesis of the double perovskite Sr2FeMoO6 has been studied based on a comparison of the particle size and structural characteristics of products from both methods. A temperature, pressure, and pH condition screening was performed, and the most representative results of these are herein presented and discussed. Radiation of microwaves in the hydrothermal synthesis method led to a decrease in crystallite size, which is an effect from the reaction temperature. The particle size ranged from 378 to 318 nm when pH was 4.5 and pressure was kept under 40 bars. According to X-ray diffraction (XRD) results coupled with the size-strain plot method, the product obtained by both synthesis methods (with and without microwave radiation) have similar crystal purity. The Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS) techniques showed that the morphology and the distribution of metal ions are uniform. The Curie temperature obtained by thermogravimetric analysis indicates that, in the presence of microwaves, the value was higher with respect to traditional synthesis from 335 K to 342.5 K. Consequently, microwave radiation enhances the diffusion and nucleation process of ionic precursors during the synthesis, which promotes a uniform heating in the reaction mixture leading to a reduction in the particle size, but keeping good crystallinity of the double perovskite. Precursor phases and the final purity of the Sr2FeMoO6 powder can be controlled via hydrothermal microwave heating on the first stages of the Sol-Gel method.

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Green synthesis and characterization of hexaferrite strontium-perovskite strontium photocatalyst nanocomposites

Main Group Metal Chemistry ◽

10.1515/mgmc-2020-0004 ◽

2020 ◽

Vol 43 (1) ◽

pp. 26-42 ◽

Cited By ~ 2

Author(s):

Zahra Hajian Karahroudi ◽

Kambiz Hedayati ◽

Mojtaba Goodarzi

Keyword(s):

Magnetic Properties ◽

Green Synthesis ◽

Sol Gel ◽

Synthesis Method ◽

Combustion Method ◽

Lemon Juice ◽

X Ray Diffraction ◽

X Ray ◽

Auto Combustion

AbstractThis study presents a preparation of SrFe12O19– SrTiO3 nanocomposite synthesis via the green auto-combustion method. At first, SrFe12O19 nanoparticles were synthesized as a core and then, SrTiO3 nanoparticles were prepared as a shell for it to manufacture SrFe12O19–SrTiO3 nanocomposite. A novel sol-gel auto-combustion green synthesis method has been used with lemon juice as a capping agent. The prepared SrFe12O19–SrTiO3 nanocomposites were characterized by using several techniques to characterize their structural, morphological and magnetic properties. The crystal structures of the nanocomposite were investigated via X-ray diffraction (XRD). The morphology of SrFe12O19– SrTiO3 nanocomposite was studied by using a scanning electron microscope (SEM). The elemental composition of the materials was analyzed by an energy-dispersive X-ray (EDX). Magnetic properties and hysteresis loop of nanopowder were characterized via vibrating sample magnetometer (VSM) in the room temperature. Fourier transform infrared spectroscopy (FTIR) spectra of the samples showed the molecular bands of nanoparticles. Also, the photocatalytic behavior of nanocomposites has been checked by the degradation of azo dyes under irradiation of ultraviolet light.

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