scholarly journals Development of an Adsorbing System Made of DMS-1 Mesh Modified by Amino Groups to Remove Pb(II) Ions from Water

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1914
Author(s):  
Viviana Palos-Barba ◽  
Cecilia Lugo-Nabor ◽  
Rodrigo R. Velázquez-Castillo ◽  
Dora Alicia Solís-Casados ◽  
Carmen L. Peza-Ledesma ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Low Cost ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Good Alternative ◽  
Ex Situ ◽  
Amino Groups ◽  
X Ray ◽  
Molar Ratios ◽  
Adsorption Processes

Water pollution by heavy metals represents several health risks. Conventional technologies employed to eliminate lead ions from residual or drinking water are expensive, therefore an efficient and low-cost technique is required and adsorption processes are a good alternative. In this work, the goal was to determine the adsorption capacity of a Disordered Mesoporous Silica 1 material (DMS-1) functionalized with amino groups, for Pb(II) ions removal. DMS-1 was prepared by sol-gel method and the incorporation of amino groups was performed by ex-situ method. As the source of amine groups, (3-Aminopropyl) triethoxysilane (APTES) was used and three different xNH2/DMS-1 molar ratios (0.2, 0.3, 0.4) were evaluated. In order to evaluate the incorporation of the amino group into the mesopore channels, thermal and structural analysis were made through Thermogravimetric Analysis (TGA), nitrogen adsorption–desorption at 77 K by Specific Brunauer–Emmett–Teller (SBET) method, Fourier Transfer Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and X-Ray Photoelectron Spectroscopy (XPS). The higher Pb(II) ions removal was achieved with the 0.3 molar proportion of xNH2/DMS-1 reaching 99.44% efficiency. This result suggests that the functionalized material can be used as an efficient adsorbent for Pb(II) ions from aqueous solution.

scholarly journals Microwave synthesis of high-quality and uniform 4 nm ZnFe2O4 nanocrystals for application in energy storage and nanomagnetics

2016 ◽  
Vol 7 ◽  
pp. 1350-1360 ◽  
Author(s):  
Christian Suchomski ◽  
Ben Breitung ◽  
Ralf Witte ◽  
Michael Knapp ◽  
Sondes Bauer ◽  
...  
Keyword(s):  
Energy Storage ◽  
Photoelectron Spectroscopy ◽  
Zinc Ferrite ◽  
Sol Gel ◽  
High Capacity ◽  
Spherical Shape ◽  
Freezing Temperature ◽  
Ex Situ ◽  
Edge Structure ◽  
X Ray

Magnetic nanocrystals with a narrow size distribution hold promise for many applications in different areas ranging from biomedicine to electronics and energy storage. Herein, the microwave-assisted sol–gel synthesis and thorough characterization of size-monodisperse zinc ferrite nanoparticles of spherical shape is reported. X-ray diffraction, 57Fe Mössbauer spectroscopy and X-ray photoelectron spectroscopy all show that the material is both chemically and phase-pure and adopts a partially inverted spinel structure with Fe3+ ions residing on tetrahedral and octahedral sites according to (Zn0.32Fe0.68)tet[Zn0.68Fe1.32]octO4±δ. Electron microscopy and direct-current magnetometry confirm the size uniformity of the nanocrystals, while frequency-dependent alternating-current magnetic susceptibility measurements indicate the presence of a superspin glass state with a freezing temperature of about 22 K. Furthermore, as demonstrated by galvanostatic charge–discharge tests and ex situ X-ray absorption near edge structure spectroscopy, the as-prepared zinc ferrite nanocrystals can be used as a high-capacity anode material for Li-ion batteries, showing little capacity fade – after activation – over hundreds of cycles. Overall, in addition to the good material characteristics, it is remarkable that the microwave-based synthetic route is simple, easily reproducible and scalable.

scholarly journals Bulk Versus Surface Modification of Alumina with Mn and Ce Based Oxides for CH4 Catalytic Combustion

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1771 ◽  
Author(s):  
Stefan Neatu ◽  
Mihaela M. Trandafir ◽  
Adelina Stănoiu ◽  
Ovidiu G. Florea ◽  
Cristian E. Simion ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Catalytic Combustion ◽  
Mixed Oxides ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Programmed ◽  
Catalytic Combustion Of Methane ◽  
Adsorption Desorption

This study presents the synthesis and characterization of lanthanum-modified alumina supported cerium–manganese mixed oxides, which were prepared by three different methods (coprecipitation, impregnation and citrate-based sol-gel method) followed by calcination at 500 °C. The physicochemical properties of the synthesized materials were investigated by various characterization techniques, namely: nitrogen adsorption-desorption isotherms, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and H2–temperature programmed reduction (TPR). This experimental study demonstrated that the role of the catalytic surface is much more important than the bulk one. Indeed, the incipient impregnation of CeO2–MnOx catalyst, supported on an optimized amount of 4 wt.% La2O3–Al2O3, provided the best results of the catalytic combustion of methane on our catalytic micro-convertors. This is mainly due to: (i) the highest pore size dimensions according to the Brunauer-Emmett-Teller (BET) investigations, (ii) the highest amount of Mn4+ or/and Ce4+ on the surface as revealed by XPS, (iii) the presence of a mixed phase (Ce2MnO6) as shown by X-ray diffraction; and (iv) a higher reducibility of Mn4+ or/and Ce4+ species as displayed by H2–TPR and therefore more reactive oxygen species.

scholarly journals Silica-Copper Oxide Composite Thin Films as Solar Selective Coatings Prepared by Dipping Sol Gel

2008 ◽  
Vol 2008 ◽  
pp. 1-5 ◽  
Author(s):  
E. Barrera-Calva ◽  
J. Méndez-Vivar ◽  
M. Ortega-López ◽  
L. Huerta-Arcos ◽  
J. Morales-Corona ◽  
...  
Keyword(s):  
Thin Films ◽  
Stainless Steel ◽  
Copper Oxide ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Silica Matrix ◽  
Composite Thin Films ◽  
X Ray ◽  
Molar Ratios ◽  
Steel Substrates

Silica-copper oxide (silica-CuO) composite thin films were prepared by a dipping sol-gel route using ethanolic solutions comprised TEOS and a copper-propionate complex. Sols with different TEOS/Cu-propionate (Si/Cu) molar ratios were prepared and applied on stainless steel substrates using dipping process. During the annealing process, copper-propionate complexes developed into particulate polycrystalline CuO dispersed in a partially crystallized silica matrix, as indicated by the X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses. The gel thermal analysis revealed that the prepared material might be stable up to400°C. The silica-CuO/stainless steel system was characterized as a selective absorber surface and its solar selectivity parameters, absorptance (α), and emittance (ε) were evaluated from UV-NIR reflectance data. The solar parameters of such a system were mostly affected by the thickness and phase composition of theSiO2-CuO film. Interestingly, the best solar parameters (α= 0.92 andε= 0.2) were associated to the thinnest films, which comprised a CuO-Cu2Omixture immersed in the silica matrix, as indicated by XPS.

Low Cost Integrated Sensors Utilizing Patterned Nano-Structured Titania Arrays Fabricated Using a Simple Process

2004 ◽  
Vol 828 ◽  
Author(s):  
Zuruzi Abu Samah ◽  
Andrei Kolmakov ◽  
Martin Moskovits ◽  
Noel C. MacDonald
Keyword(s):  
Photoelectron Spectroscopy ◽  
Low Cost ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Aqueous Hydrogen Peroxide ◽  
X Ray ◽  
Sensing Systems ◽  
Potential Applications ◽  
Nano Wires ◽  
Low Temperature Process

ABSTRACTUsing a novel low-temperature process, we demonstrate the facile integration of crack-free nanostructured titania (NST) as sensing elements in microsystems. Unlike conventional sol-gel methods, NST layers of interconnected nano-walls and nano-wires were formed by reacting Ti surfaces with aqueous hydrogen peroxide solution. Cracks were observed in NST layers formed on blanket Ti films but absent on arrays of patterned Ti pads below a threshold dimension. Analyses using TEM, high resolution SEM, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) reveal that NST consists of anatase TiO2 nano-crystals. NST pads were found able to detect oxygen gas of a few ppm. NST pad arrays were integrated on rigid and flexible substrates with potential applications in low cost and wearable sensing systems.

scholarly journals Adsorption of Hexavalent Chromium Using Banana Pseudostem Biochar and Its Mechanism

2018 ◽  
Vol 10 (11) ◽  
pp. 4250 ◽  
Author(s):  
Shuang Xu ◽  
Weiguang Yu ◽  
Sen Liu ◽  
Congying Xu ◽  
Jihui Li ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Pyrolysis Temperature ◽  
Low Cost ◽  
Surface Adsorption ◽  
Maximum Adsorption Capacity ◽  
X Ray ◽  
Adsorption Processes ◽  
Different Temperatures ◽  
Pseudo Second Order ◽  
Porosity Analysis

A low-cost biochar was prepared through slow pyrolysis of banana pseudostem biowaste at different temperatures, and characterized by surface area and porosity analysis, scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). It was shown that the biochar prepared at low pyrolysis temperature was rich in oxygen-containing groups on the surface. Adsorption experiments revealed that the biochar prepared at 300 °C (BB300) was the best adsorbent for Cr(VI) with 125.44 mg/g maximum adsorption capacity at pH 2 and 25 °C. All the adsorption processes were well described by pseudo-second-order and Langmuir models, indicating a monolayer chemiadsorption. Furthermore, it was demonstrated that adsorption of Cr(VI) was mainly attributed to reduction of Cr(VI) to Cr(III) followed by ion exchange and complexation with the biochar.

Diatomite modified by TiO2 for adsorption of U(VI)

2018 ◽  
Vol 106 (9) ◽  
pp. 733-742 ◽  
Author(s):  
Ni Yuan ◽  
Peng Liu ◽  
Wangsuo Wu
Keyword(s):  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Water Environment ◽  
X Ray ◽  
Ph Values ◽  
Batch Technique ◽  
Adsorption Processes ◽  
Novel Material ◽  
Pseudo Second Order ◽  
Synthesized Materials

Abstract Diatomite was modified with TiO2. The synthesized materials were characterized and used for removal of U(VI) from aqueous solutions. The influences of pH, contact time and temperature on U(VI) adsorption onto TiO2@diatomite were studied by batch technique, and X-ray photoelectron spectroscopy (XPS) was employed to analyze the experimental data. We compared the adsorption of U(VI) onto natural diatomite, TiO2 and TiO2@diatomite made by sol-gel method. The dynamic process showed that the adsorption of U(VI) onto TiO2@diatomite matched the pseudo-second-order kinetics model, and the adsorption of U(VI) was significantly dependent on pH values. Through simulating the adsorption isotherms by Langmuir, Freundlich and Dubini–Radushkevich (D–R) models, respectively, it could be seen that the adsorption patterns of U(VI) onto TiO2@diatomite were mainly controlled by surface complexation, and the adsorption processes were endothermic and spontaneous. The modification of diatomite by TiO2 shows a novel material for removing U(VI) from water environment for industrialized application.

Sol-gel Synthesis of Li–ZrSiO4

2000 ◽  
Vol 15 (7) ◽  
pp. 1490-1495 ◽  
Author(s):  
Heriberto Pfeiffer ◽  
Pedro Bosch ◽  
Jose A. Odriozola ◽  
Alberto Lopez ◽  
Jorge A. Ascencio ◽  
...  
Keyword(s):  
Theoretical Analysis ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Molar Ratio ◽  
Spectroscopy Analysis ◽  
Gel Method ◽  
X Ray ◽  
Cell Parameters ◽  
Molar Ratios ◽  
Sol Gel Synthesis

Li–ZrSiO4 was synthesized by the sol-gel method. Reactions were performed with different Li:Zr molar ratios: 1, 3, 5, and 6. Cell parameters changed as follows: a0 decreased and c0 increased as the Li:Zr molar ratio increased. The x-ray photoelectron spectroscopy analysis showed two kinds of oxygen atoms. The first one was attributed to ZrSiO4 oxygens. The second one was attributed to Li–O bonds. All these results were supported by a theoretical analysis. It was concluded that lithium atoms were held in interstitial positions of the ZrSiO4 structure.

scholarly journals Visible Light Sensitive SnO2/ZnCo2O4 Material for the Photocatalytic Removal of Organic Pollutants in Water

Inorganics ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 77 ◽  
Author(s):  
Hadj Benhebal ◽  
Cédric Wolfs ◽  
Samir Kadi ◽  
Rémi G. Tilkin ◽  
Boualem Allouche ◽  
...  
Keyword(s):  
Visible Light ◽  
Organic Pollutants ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
X Ray ◽  
Photocatalytic Removal ◽  
Sol Gel Process ◽  
Loading Ratio ◽  
Adsorption Desorption

In this study, pure ZnCo2O4 and SnO2/ZnCo2O4 mix photocatalysts have been synthesized by the sol-gel process with three different SnO2 loading percentages (10, 20, and 30 wt %). Their photocatalytic activities were assessed on the degradation of organic pollutants in water under visible illumination. The structural, morphological, and optical properties were analyzed by X-ray diffraction (XRD), scanning electron microscopy, energy-dispersive X-ray (EDX), Fourier transform infrared (FTIR), nitrogen adsorption-desorption isotherms, X-ray photoelectron spectroscopy (XPS), and UV–Visible diffuse reflectance measurements. The results have shown that the materials are composed of a crystalline ZnCo2O4 matrix with a decrease in crystallite size with the amount of SnO2. Weakly crystalline SnO2 is also observed for loaded samples. The specific surface area is modified with the loading ratio. The evaluation of the photoactivity of the samples under visible light for the degradation of p-nitrophenol has highlighted that all materials are highly photoactive under visible light thanks to heterojunction between the two oxides. An application test has been conducted on a dye, congo red, showing the same tendencies. An optimal amount of SnO2 loading is observed for the sample containing 20 wt % of SnO2. A comparison with commercial Evonik P25 showed that the materials developed in this work have five to six times better efficiency under visible light, leading to a promising photocatalyst material.

scholarly journals CoMn2O4 Catalyst Prepared Using the Sol-Gel Method for the Activation of Peroxymonosulfate and Degradation of UV Filter 2-Phenylbenzimidazole-5-sulfonic Acid (PBSA)

Nanomaterials ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 774 ◽  
Author(s):  
Chihao Lin ◽  
Dejian Shi ◽  
Zhentao Wu ◽  
Lingfeng Zhang ◽  
Zhicai Zhai ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Sulfonic Acid ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Paramagnetic Resonance ◽  
Uv Filter ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method

In this study, a bimetallic oxide catalyst of cobalt-manganese (CoMn2O4) was synthesized using the sol-gel method, and it was then characterized using a variety of techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) spectroscopy, X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption–desorption isotherms. The obtained novel catalyst, i.e., CoMn2O4, was then used as an activator of peroxymonosulfate (PMS) for the catalytic degradation of a commonly-used UV filter, 2-phenylbenzimidazole-5-sulfonic acid (PBSA) in water. The effects of various factors (e.g., catalyst dosage, PMS concentration, reaction temperature, and pH) in the process were also evaluated. Chemical scavengers and electron paramagnetic resonance (EPR) tests showed that the •OH and SO4•− were the main reactive oxygen species. Furthermore, this study showed that CoMn2O4 is a promising catalyst for activating PMS to degrade the UV filters.

scholarly journals Characterization of Photoactive Fe-TiO2 Lime Coatings for Building Protection: The Role of Iron Content

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1847 ◽  
Author(s):  
Chrysi Kapridaki ◽  
Nikolaos Xynidis ◽  
Eleftheria Vazgiouraki ◽  
Nikolaos Kallithrakas-Kontos ◽  
Pagona Maravelaki-Kalaitzaki
Keyword(s):  
Tio2 Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Visible Radiation ◽  
Edge Structure ◽  
Doped Tio2 ◽  
X Ray ◽  
Vis Spectroscopy

Iron-doped TiO2 nanoparticles, ranging in Fe concentrations from 0.05 up to 1.00% w/w, were synthesized through a simple sol-gel method. Fourier-transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), Ultraviolet-Visible (UV-Vis) spectroscopy, nitrogen adsorption−desorption isotherms, X-ray photoelectron spectroscopy (XPS), and X-ray absorption near-edge structure spectroscopy (XANES) were used to characterize the synthesized nanoparticles. The characterization of the Fe-doped TiO2 nanoparticles revealed the predominant presence of anatase crystalline form, as well as the incorporation of the Fe3+ ions into the crystal lattice of TiO2. The photocatalytic assessment of the Fe-doped TiO2 nanoparticles indicated that the low iron doping titania (0.05 and 0.10% w/w) have a positive effect on the photocatalytic degradation of Methyl Orange under visible radiation. Moreover, FTIR monitoring of calcium hydroxide pastes enriched with low Fe-doped TiO2 revealed enhancement of carbonation at both early and later stages. Improved photocatalytic performance and increased lime carbonation, observed in lime coatings with low Fe-doped TiO2 admixtures, established them as invaluable contributors to the protection of the built environment.

Sign in / Sign up

Export Citation Format

Share Document