scholarly journals Enhanced Potential Toxic Metal Removal Using a Novel Hierarchical SiO2–Mg(OH)2 Nanocomposite Derived from Sepiolite

Minerals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 298 ◽  
Author(s):  
Qi-Zhi Yao ◽  
Sheng-Hui Yu ◽  
Tian-Lei Zhao ◽  
Fei-Jin Qian ◽  
Han Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Heavy Metals ◽  
Metal Removal ◽  
Structural Characteristics ◽  
High Surface ◽  
High Surface Area ◽  
Raw Material ◽  
Amorphous Sio2 ◽  
X Ray ◽  
Wide Range

Clays are widely used as sorbents for heavy metals due to their high specific surface areas, low cost, and ubiquitous occurrence in most soil and sediment environments. However, the low loading capacity for heavy metals is one of their inherent limitations. In this work, a novel SiO2–Mg(OH)2 nanocomposite was successfully prepared via sequential acid–base modification of raw sepiolite. The structural characteristics of the resulting modified samples were characterized by a wide range of techniques including field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and nitrogen physisorption analysis. The results show that a hierarchical nanocomposite constructed by loading the Mg(OH)2 nanosheets onto amorphous SiO2 nanotubes can be successfully prepared, and the nanocomposite has a high surface area (377.3 m2/g) and pore volume (0.96 cm3/g). Batch removal experiments indicate that the nanocomposite exhibits high removal efficiency toward Gd(III), Pb(II), and Cd(II), and their removal capacities were greatly enhanced in comparison with raw sepiolite, due to the synergistic effect of the different components in the hierarchical nanocomposite. This work can provide a novel route toward a hierarchical nanocomposite by using clay minerals as raw material. Taking into account the simplicity of the fabrication route and the high loading capacities for heavy metals, the developed nanocomposite also has great potential applications in water treatment.

scholarly journals Nanostructured faujasite zeolite as metal ion adsorbent: kinetics, equilibrium adsorption and metal recovery studies

2020 ◽  
Author(s):  
Mariana B. Goncalves ◽  
Djanyna V. C. Schmidt ◽  
Fabiana S. dos Santos ◽  
Daniel F. Cipriano ◽  
Gustavo R. Gonçalves ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Metal Ions ◽  
Metal Ion ◽  
Active Sites ◽  
Metal Removal ◽  
High Surface ◽  
High Surface Area ◽  
Kinetic Studies ◽  
Crystallization Time ◽  
X Ray

Abstract The hydrothermal synthesis of nano-faujasite has been successfully performed and the effects of some crystallization parameters were investigated, along with the use of this material as a heavy-metal ion adsorbent. X-ray diffraction patterns have shown that the structure of the nano-faujasite is strongly dependent on both the crystallization time and the alkalinity of the synthesis medium. According to N2 physisorption, X-ray fluorescence, SEM/EDS, and solid state 29Si and 27Al NMR data, the produced nano-faujasite consists of a solid with low molar Si/Al ratio (1.7), with high availability of ion exchange sites and high surface area/small particle size, allowing easy diffusion of metal ions to adsorbent active sites. As a consequence, an excellent performance on removal of Cd2+, Zn2+ and Cu2+ ions was found for this solid. The adsorption capacity followed the order Cd2+ (133 mg·g−1) > Zn2+ (115 mg·g−1) > Cu2+ (99 mg·g−1), which agrees with the order of increasing absolute values of the hydration energy of the metal ions. Kinetic studies and adsorption isotherms showed that the metal ion removal takes place by ion exchange on the monolayer surface of the nano-faujasite. The electrochemical recovery of copper in metallic form exhibited an efficiency of 80.2% after 120 min, which suggests that this process can be adequately implemented for full-scale metal removal.

Ni-doped, urchin-like Bi2S3 particles for electrocatalytic oxidation of glucose

2021 ◽  
pp. 2150006
Author(s):  
Biao Wang ◽  
Ya Liu ◽  
Xu Huai ◽  
Yuqing Miao
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Electrocatalytic Oxidation ◽  
High Surface ◽  
High Surface Area ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Capacitance Current ◽  
Oxidation Of Glucose

In order to develop non-noble metal-based electrocatalysts for glucose oxidation, the Ni-doped, urchin-like Bi2S3 particles were prepared by a solvothermal method using the solvent of ethylene glycol/H2O. The obtained products were characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and X-ray diffraction. The background signal from capacitance current is relatively low and the electrocatalytic oxidation current of glucose relatively high due to the urchin-like nanostructure of Bi2S3 particles and high surface area where the presence of Bi also improves the electrocatalytic performance of NiII/NiIII shift.

SYNTHESIS AND CHARGE–DISCHARGE PROPERTIES OF POROUS CO3O4 NANOROD BUNDLE ELECTRODE

NANO ◽  
2012 ◽  
Vol 07 (05) ◽  
pp. 1250036 ◽  
Author(s):  
FEI TENG ◽  
JUN WANG ◽  
MINDONG CHEN ◽  
DENNIS DESHENG MNEG
Keyword(s):  
Electron Microscopy ◽  
High Surface ◽  
High Surface Area ◽  
Lithium Ion ◽  
Nitrogen Adsorption ◽  
X Ray ◽  
Transmission Electron ◽  
Rate Capacity ◽  
Nanorod Bundle ◽  
Charge Discharge

The Co3O4 nanorod bundles are synthesized by a hydrothermal method. The samples are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron diffraction (ED), X-ray powder diffractometer (XRD), and nitrogen adsorption. It is important that the as-obtained Co3O4 nanorod bundles are assembled by nanoparticles. The porous nanorod bundle electrode exhibits a higher rate capacity and a higher reverse capability for lithium ion battery than the solid nanorods, which is attributed to the high surface area and the porous structure.

scholarly journals Study of Photodegradation Performance and Ability of Lead Removal of Synthesized Maghemite Nanoparticles Using Ziziphus Jujuba Extract

2021 ◽  
Author(s):  
Abdolhossein Miri ◽  
Atefeh Sadat Sedighi ◽  
Ahmad Najafidoust ◽  
Mehrdad Khatami ◽  
Mina sarani
Keyword(s):  
Heavy Metals ◽  
Methylene Blue ◽  
High Efficiency ◽  
High Surface ◽  
High Surface Area ◽  
Good Alternative ◽  
Lead Removal ◽  
Maghemite Nanoparticles ◽  
X Ray ◽  
Ziziphus Jujuba

Abstract Today, Water pollutants such as heavy metals and dyes are very important dangers to the nature. Metals such as lead, chromium, mercury and arsenic are examples of heavy metals which are toxic to living things, even sometime at the lowest concentrations. For resolve this challenge, Magnetic nanoparticles are attractive compound because of their advantages such as high efficiency, fast recovery capability, high surface area, easy transportation and inexpensive. We presented an easy and eco-friendly route for the synthesis of iron oxide nanoparticles using Ziziphus jujuba extract. In order to determine the physical, chemical and optical properties of the synthesized samples, Fourier-transform infrared (FT-IR), powder X-ray diffraction (PXRD), vibrating sample magnetometer (VSM), field emission scanning electron microscope (FESEM), energy dispersive X-ray (EDX), transmission electron microscopy (TEM), and Raman analyses were deployed. PXRD results showed that the synthesized nanoparticles have maghemite form of (γ-Fe2O3). FESEM and TEM results demonstrated that the size of these nanoparticles was in range of 20-50 nm, and had spherical shapes. Raman spectrum confirmed the cubic structure of γ-Fe2O3 NPs. Survey of magnetic properties showed that the synthesized maghemite nanoparticles (γ-Fe2O3 NPs) were superparamagnetic. The ability to remove lead from aqueous solution was investigated using these nanoparticles. The results showed that the synthesized nanoparticles were capable of removing 96% of lead at pH = 7 and 1 mg/L loading of nanoparticles. The photocatalytic activity of γ-Fe2O3 NPs was studied on methylene blue (MB) dye; as a result, MB at pH =7 and 1 gr dosage of γ-Fe2O3 had the highest removal percentage (92.8%) during 160 minute using γ-Fe2O3 which calcined at 400 ˚C. The reusability results showed that after four cycles of using the γ-Fe2O3-400, the obtained degradation of methylene blue was about 87.1%. Thus, synthesized γ-Fe2O3 NPs can be a good alternative for removing heavy metals and industrial dyes from contaminated waters.

Characterization of an Inorganic Cryptomelane Nanomaterial Synthesized by a Novel Process Using Transmission Electron Microscopy and X-Ray Diffraction

2008 ◽  
Vol 14 (4) ◽  
pp. 328-334 ◽  
Author(s):  
Longzhou Ma ◽  
Thomas Hartmann ◽  
Marcos A. Cheney ◽  
Nancy R. Birkner ◽  
Pradip K. Bhowmik
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Surface ◽  
High Surface Area ◽  
Rietveld Analysis ◽  
X Ray ◽  
Transmission Electron ◽  
Potential Applications ◽  
Diffraction Patterns ◽  
Crystallographic Planes

Layer- and tunnel-structured manganese oxide nanomaterials are important because of their potential applications in industrial catalysis. A novel soft chemistry method was developed for the synthesis of inorganic cryptomelane nanomaterials with high surface area. Bright field transmission electron microscopy (BF-TEM) and high-resolution transmission electron microscopy (HRTEM) techniques were employed to characterize this nanomaterial. A nanosized material with fibrous texture comprised of 140–160 nm striations was identified by BF-TEM imaging. HRTEM images show multiple atomic morphologies such as “helix-type,” “doughnut-like,” and tunnel structures lying on different crystallographic planes. The crystallographic parameters of this material were analyzed and measured by X-ray powder diffraction (XRD) showing that the synthesized nanomaterial is single phased and corresponds to cryptomelane with major diffraction peaks (for 10° < 2θ < 60°) at d-spacing values of 6.99, 4.94, 3.13, 2.40, 2.16, 1.84, 1.65, and 1.54 Å. A “doughnut-like” crystal structure was confirmed based on the crystallographic data. Structure and lattice parameters refinement was performed by XRD/Rietveld analysis. Simple simulation of HRTEM images and selected area diffraction patterns were applied to interpret the HRTEM images as observed.

scholarly journals Synthesis and characterization of LaMnO3 nanocrystals and graphene oxide: fabrication of graphene oxide–LaMnO3 sensor for simultaneous electrochemical determination of hydroquinone and catechol

2019 ◽  
Vol 9 (4) ◽  
pp. 255-267 ◽  
Author(s):  
Sedighe Akbari ◽  
Mohammad Mehdi Foroughi ◽  
Hadi Hassani Nadiki ◽  
Shohreh Jahani
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Simultaneous Determination ◽  
High Surface ◽  
High Surface Area ◽  
Electrochemical Determination ◽  
Great Decrease ◽  
X Ray ◽  
Transmission Electron

For the first time, a new method for preparation of graphene oxide-LaMnO3 (GO-LaMnO3) nanocompositeas a material of electrochemical sensor for simultaneous determination of catechol (CT) and hydroquinone (HQ) is developed. LaMnO3 nanoparticles have been characterized by Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM) and energy dispersive X-ray analysis (EDX) technique. Due to the excellent catalytic activity, enhanced electrical conductivity and high surface area, the simultaneous determination of HQ and CT with two well-defined peaks has been achieved at the GO-LaMnO3 modified electrode. Comparing with unmodified electrodes, the oxidation currents of HQ and CT increased remarkably. Also, the result exhibited a great decrease in anodic overpotentialresulting in about 150 mV negative shift of potential. The catalytic peak current values are found linearly dependent on the HQ and CT concentrations in the range of 0.5–433.3 and 0.5–460.0 μM with sensitivity of 0.0719 and 0.0712 μA μM-1, respectively. The detection limits for HQ and CT are determined as 0.06 and 0.05 μM, respectively.

scholarly journals Photocatalytic Degradation of Allura Red by MN-Ni Co-Doped Nanotitania under Visible Light Irradiation

2019 ◽  
Vol 8 (12) ◽  
pp. 650-657
Keyword(s):  
Electron Microscopy ◽  
Anatase Phase ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
X Ray ◽  
Allura Red ◽  
Co Doping ◽  
Ft Ir ◽  
Co Doped

Photocatalyst has been extensive interest because of it’s new innovation to the reduce the contamination in the environment. A straight forward and economical procedure has been employed by sol-gel technique for the co-doping of Mn2+ and Ni2+ into TiO2 . The co-doped and undoped photocatalysts were described by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive X-ray Spectroscopy (EDX), Fourier transform infrared spectroscopy (FT-IR), UV-Visible Diffused Reflectance Spectroscopy (UV Vis-DRS), Transmission electron Microscopy (TEM) and Brunauer-Emmett-Teller (BET). The portrayal results shows that anatase and rutile mixed phase was observed for some co-doped nanocatalysts and the remaining catalysts exhibits anatase phase only. It was observed by FT-IR that the shifting of frequency of Ti-O-Ti in the catalysts was seen due to substitutional doping of Mn and Ni by replace Ti and O, further the photocatalysts shows rough morphology, irregular shape of particle with size (6.5nm) and having high surface area (135.70 m2/g), less band energy (2.7 eV). The photocatalytic action of these materials was assessed by the degradation of Allura red (AR) as a contaminant. The results shows that AR has degraded within 60 minutes at doping concentrations 0.25 Wt% of Mn2+ion and 1.0 Wt% of Ni2+ ion in TiO2 (NMT2) at an optimum reaction parameters pH-4, catalyst dose 0.070g/L and at AR initial dye concentration 0.010g/L.

scholarly journals Preparation of modified paints with nano-structured additives and its potential applications

2020 ◽  
Vol 10 ◽  
pp. 184798042090918
Author(s):  
Ricardo Solano ◽  
David Patiño-Ruiz ◽  
Adriana Herrera
Keyword(s):  
Electron Microscopy ◽  
Zno Nanoparticles ◽  
Uv Light ◽  
High Surface ◽  
High Surface Area ◽  
Antibacterial Properties ◽  
Normal Function ◽  
High Porosity ◽  
X Ray ◽  
Self Cleaning

Recently, an increase in the production of intelligent nanomaterials has been reported for the application of solid surface coating. These nanomaterials provide a wide number of functionalities such as anticorrosive, antibacterial, and self-cleaning properties. Hence, titanium dioxide (TiO2) and zinc oxide (ZnO) nanoparticles were synthesized using a green chemistry approach. These nanoparticles were fully characterized by scanning electron microscopy, energy-dispersive X-ray, high-resolution transmission electron microscopy, X-ray diffraction, ultraviolet (UV)–visible spectroscopy, Brunauer–Emmett–Teller test, and nitrogen adsorption–desorption isotherm. Then, a commercial enamel-type paint was modified by using different concentrations (2, 3.5, and 5 w/v%) of nanoparticles. These nanofilled paints were then brushed onto the surface of different types of materials such as carbon steel sheets, wood sheets, and aluminum disks. Anticorrosive, self-cleaning, and antibacterial properties of the nanofilled paints were evaluated, with the aim to determine the capability for this application. According to the characterization results, TiO2 and ZnO nanoparticles exhibited similar physicochemical properties compared to those synthesized using traditional methods. The anticorrosion results revealed that nanofilled paints provide a barrier using low concentrations of nanoparticles, due to the decrease of agglomerates on the surface avoiding the presence of high porosity. In the case of self-cleaning, a proposed mechanism of degradation demonstrated that the presence of both nanoparticles in the paint provided high degradation of methylene blue due to the high surface area offered by the nanoparticles. On the other hand, antibacterial activity under UV light was observed only for ZnO nanoparticles, which may be related to the diffusion of nanoparticles into the cell membrane of the bacteria, affecting the normal function. These results showed to be promising for the modification of paints with TiO2 and ZnO nanoparticles, and the application on solid surfaces for the construction, and even in textile fields.

scholarly journals Understanding Pore Surface Modification of Sucrose-Modified Iron Oxide/Silica Mesoporous Composite for Degradation of Methylene Blue

2021 ◽  
Vol 16 (3) ◽  
pp. 459-471
Author(s):  
Yuvita Eka Pertiwi ◽  
Maria Ulfa ◽  
Teguh Endah Saraswati ◽  
Didik Prasetyoko ◽  
Wega Trisunaryanti
Keyword(s):  
Methylene Blue ◽  
Iron Oxide ◽  
Surface Area ◽  
Heterogeneous Reaction ◽  
High Surface ◽  
High Surface Area ◽  
Impregnation Method ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Wide Range

Santa Barbara Amorphous (SBA-15) containing iron oxide with a sucrose-modified in a heterogeneous reaction for degradation methylene blue (MB) successful synthesized used hydrothermal, ultrasonication, and wet impregnation method. SBA-15 is mesoporous silica that can easily serve as external and internal surfaces making it suitable for a wide range of applications. The structure and morphology of materials were characterized using Surface Area Analyzer (SAA), X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope-Energy Dispersive X-Ray (SEM-EDX), and Transmission Electron Microscopy (TEM). Iron oxide impregnated as a maghemite phase has an average size of 12 nm and well distributed on the SBA-15. After modified with sucrose the materials remaining stable, which has a two-dimensional hexagonal (p6mm) structure, high specific surface area, and large pore volume (up to 1.82 cm3.g−1). The degradation of MB was evaluated under visible light irradiation using UV-Vis spectroscopy. Catalytic activity showed efficiencies of 52.9; 70.2; and 21.1% for SBA-15, Fe2O3/SBA-15, and sucrose-modified Fe2O3/SBA-15 respectively. Sucrose-modified Fe2O3/SBA-15 has the lowest efficiency, which probably occurs due to the presence of pore-blocking and the formation of micropores on the external pore. The modification with sucrose has the advantage of producing a high surface area even though there is a catalytic center due to partial decomposition which causes a decrease in the efficiency of degradation of MB. All materials provide a high micro surface area so that they can be further adapted and can be widely applied to many potential applications as both catalyst support and an adsorbent. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 

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