scholarly journals Preparation of Micro-Nano Material Composed of Oyster Shell/Fe3O4 Nanoparticles/Humic Acid and Its Application in Selective Removal of Hg(II)

Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 953 ◽  
Author(s):  
Chuxian He ◽  
Junhao Qu ◽  
Zihua Yu ◽  
Daihuan Chen ◽  
Tiantian Su ◽  
...  
Keyword(s):  
Humic Acid ◽  
Fe3o4 Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
Raw Materials ◽  
Oyster Shell ◽  
Solution Concentration ◽  
Precipitation Method ◽  
Maximum Adsorption Capacity ◽  
X Ray ◽  
Isotherm Equation

Micro-nano composite material was prepared to adsorb Hg(II) ions via the co-precipitation method. Oyster shell (OS), Fe3O4 nanoparticles, and humic acid (HA) were used as the raw materials. The adhesion of nanoparticles to OS displayed by scanning electron microscopy (SEM), the appearance of the (311) plane of standard Fe3O4 derived from X-ray diffraction (XRD), and the transformation of pore sizes to 50 nm and 20 μm by mercury intrusion porosimetry (MIP) jointly revealed the successful grafting of HA-functionalized Fe3O4 onto the oyster shell surface. The vibrating sample magnetometer (VSM) results showed superparamagnetic properties of the novel adsorbent. The adsorption mechanism was investigated based on X-ray photoelectron spectroscopy (XPS) techniques, which showed the process of physicochemical adsorption while mercury was adsorbed as Hg(II). The effects of pH (3–7), initial solution concentration (2.5–30 mg·L−1), and contact time (0–5 h) on the adsorption of Hg(II) ions were studied in detail. The experimental data were well fitted to the Langmuir isotherm equation (R2 = 0.991) and were shown to follow a pseudo-second-order reaction model (R2 = 0.998). The maximum adsorption capacity of Hg(II) was shown to be 141.57 mg·g−1. In addition, this new adsorbent exhibited excellent selectivity.

scholarly journals Efficient Adsorption of Methylene Blue by Porous Biochar Derived from Soybean Dreg Using a One-Pot Synthesis Method

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 661
Author(s):  
Zhiwei Ying ◽  
Xinwei Chen ◽  
He Li ◽  
Xinqi Liu ◽  
Chi Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Methylene Blue ◽  
Photoelectron Spectroscopy ◽  
Synthesis Method ◽  
Urban Pollution ◽  
Maximum Adsorption Capacity ◽  
One Pot ◽  
Average Pore ◽  
X Ray ◽  
Isotherm Equation

Soybean dreg is a by-product of soybean products production, with a large consumption in China. Low utilization value leads to random discarding, which is one of the important sources of urban pollution. In this work, porous biochar was synthesized using a one-pot method and potassium bicarbonate (KHCO3) with low-cost soybean dreg (SD) powder as the carbon precursor to investigating the adsorption of methylene blue (MB). The prepared samples were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), elemental analyzer (EA), Brunauer-Emmett-Teller (BET), X-ray diffractometer (XRD), Raman spectroscopy (Raman), Fourier transform infrared spectrometer (FTIR), and X-ray photoelectron spectroscopy (XPS). The obtained SDB-K-3 showed a high specific surface area of 1620 m2 g−1, a large pore volume of 0.7509 cm3 g−1, and an average pore diameter of 1.859 nm. The results indicated that the maximum adsorption capacity of SDB-K-3 to MB could reach 1273.51 mg g−1 at 318 K. The kinetic data were most consistent with the pseudo-second-order model and the adsorption behavior was more suitable for the Langmuir isotherm equation. This study demonstrated that the porous biochar adsorbent can be prepared from soybean dreg by high value utilization, and it could hold significant potential for dye wastewater treatment in the future.

Molecularly Imprinted TiO2/WO3-Coated Magnetic Nanocomposite for Photocatalytic Degradation of 4-Nitrophenol Under Visible Light

2016 ◽  
Vol 69 (6) ◽  
pp. 638 ◽  
Author(s):  
Shoutai Wei ◽  
Hualong Liu ◽  
Chiyang He ◽  
Ying Liang
Keyword(s):  
Visible Light ◽  
Photocatalytic Degradation ◽  
Fe3o4 Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Energy Resource ◽  
Precipitation Method ◽  
Adsorption Ability ◽  
Molecularly Imprinted ◽  
X Ray

In this paper, a molecularly imprinted TiO2/WO3-coated magnetic Fe3O4@SiO2 nanocomposite was developed for photocatalytic degradation. Fe3O4 nanoparticles were first prepared by a traditional co-precipitation method, and then a SiO2 shell was grown on the surface of the Fe3O4 nanoparticles. Finally, a 4-nitrophenol imprinted TiO2/WO3 coating was obtained on the surface of the Fe3O4@SiO2 nanocomposite via a sol-gel method and subsequent calcination. The new composite was characterised by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), high resolution TEM (HRTEM) and vibrating sample magnetometry (VSM). In addition, the adsorption ability and photocatalytic activity of the composite were investigated. Results showed that the imprinted composite had higher adsorption ability for the template than the non-imprinted composite. The imprinted catalyst could degrade 4-nitrophenol under visible light with a first-order reaction rate of 0.1039 h–1, which was ~2.5 times that of the non-imprinted catalyst. The new imprinted catalyst showed good catalytic selectivity, an ease of being recycled by an external magnetic field, good reusability, no need for additional chemicals, and allows the possibility of utilising solar light as energy resource. Therefore, the catalyst can be potentially applied for ‘green’, low-cost and effective degradation of 4-nitrophenol in real wastewater.

Effect of nano-sized cerium–zirconium oxide solid solution on far-infrared emission properties of tourmaline powders

2015 ◽  
Vol 29 (30) ◽  
pp. 1550183 ◽  
Author(s):  
Bin Guo ◽  
Liqing Yang ◽  
Weijie Hu ◽  
Wenlong Li ◽  
Haojing Wang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Raw Materials ◽  
Reference Sample ◽  
Far Infrared ◽  
Infrared Emission ◽  
Emission Property ◽  
Precipitation Method ◽  
Xps Spectra ◽  
X Ray ◽  
Emission Properties

Far-infrared functional nanocomposites were prepared by the co-precipitation method using natural tourmaline [Formula: see text], where [Formula: see text] is [Formula: see text], [Formula: see text], [Formula: see text], or vacancy; [Formula: see text] is [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], or [Formula: see text]; [Formula: see text] is [Formula: see text], [Formula: see text], [Formula: see text], or [Formula: see text]; [Formula: see text] is [Formula: see text], [Formula: see text]; and [Formula: see text] is [Formula: see text], [Formula: see text], or [Formula: see text] powders, ammonium cerium(IV) nitrate and zirconium(IV) nitrate pentahydrate as raw materials. The reference sample, tourmaline modified with ammonium cerium(IV) nitrate alone was also prepared by a similar precipitation route. The results of Fourier transform infrared spectroscopy show that tourmaline modified with Ce and Zr has a better far-infrared emission property than tourmaline modified with Ce alone. Through characterization by transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), the mechanism for oxygen evolution during the heat process in the two composite materials was systematically studied. The XPS spectra show that [Formula: see text] ratio inside tourmaline modified with Ce alone can be raised by doping Zr. Moreover, it is showed that there is a higher [Formula: see text] ratio inside the tourmaline modified with Ce and Zr than tourmaline modified with Ce alone. In addition, XRD results indicate the formation of [Formula: see text] and [Formula: see text] crystallites during the heat treatment and further TEM observations show they exist as nanoparticles on the surface of tourmaline powders. Based on these results, we attribute the improved far-infrared emission properties of Ce–Zr doped tourmaline to the enhanced unit cell shrinkage of the tourmaline arisen from much more oxidation of [Formula: see text] to [Formula: see text] inside the tourmaline caused by the change in the catalyst redox properties of [Formula: see text] brought about by doping with [Formula: see text]. In all samples, tourmaline modified with 7.14 wt.% Ce and 1.86 wt.% Zr calcined at 800[Formula: see text]C for 5 h has the best far-infrared emission property with the maximum emissivity value of 98%.

scholarly journals Improved Water–Gas Shift Performance of Au/NiAl LDHs Nanostructured Catalysts via CeO2 Addition

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 366
Author(s):  
Margarita Gabrovska ◽  
Ivan Ivanov ◽  
Dimitrinka Nikolova ◽  
Jugoslav Krstić ◽  
Anna Maria Venezia ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Nanostructured Catalysts ◽  
Water Gas Shift ◽  
Precipitation Method ◽  
Conversion Degree ◽  
Pure Hydrogen ◽  
Medium Temperature ◽  
X Ray ◽  
Supported Gold ◽  
Water Gas

Supported gold on co-precipitated nanosized NiAl layered double hydroxides (LDHs) was studied as an effective catalyst for medium-temperature water–gas shift (WGS) reaction, an industrial catalytic process traditionally applied for the reduction in the amount of CO in the synthesis gas and production of pure hydrogen. The motivation of the present study was to improve the performance of the Au/NiAl catalyst via modification by CeO2. An innovative approach for the direct deposition of ceria (1, 3 or 5 wt.%) on NiAl-LDH, based on the precipitation of Ce3+ ions with 1M NaOH, was developed. The proposed method allows us to obtain the CeO2 phase and to preserve the NiAl layered structure by avoiding the calcination treatment. The synthesis of Au-containing samples was performed through the deposition–precipitation method. The as-prepared and WGS-tested samples were characterized by X-ray powder diffraction, N2-physisorption and X-ray photoelectron spectroscopy in order to clarify the effects of Au and CeO2 loading on the structure, phase composition, textural and electronic properties and activity of the catalysts. The reduction behavior of the studied samples was evaluated by temperature-programmed reduction. The WGS performance of Au/NiAl catalysts was significantly affected by the addition of CeO2. A favorable role of ceria was revealed by comparison of CO conversion degree at 220 °C reached by 3 wt.% CeO2-modified and ceria-free Au/NiAl samples (98.8 and 83.4%, respectively). It can be stated that tuning the properties of Au/NiAl LDH via CeO2 addition offers catalysts with possibilities for practical application owing to innovative synthesis and improved WGS performance.

scholarly journals Pristine and Magnetic Kenaf Fiber Biochar for Cd2+ Adsorption from Aqueous Solution

2021 ◽  
Vol 18 (15) ◽  
pp. 7949
Author(s):  
Anwar Ameen Hezam Saeed ◽  
Noorfidza Yub Harun ◽  
Suriati Sufian ◽  
Muhammad Roil Bilad ◽  
Zaki Yamani Zakaria ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Textural Properties ◽  
Ion Concentration ◽  
Solution Temperature ◽  
Maximum Adsorption Capacity ◽  
Magnetic Biochar ◽  
X Ray ◽  
Study Results ◽  
Capacity Surface

Development of strategies for removing heavy metals from aquatic environments is in high demand. Cadmium is one of the most dangerous metals in the environment, even under extremely low quantities. In this study, kenaf and magnetic biochar composite were prepared for the adsorption of Cd2+. The synthesized biochar was characterized using (a vibrating-sample magnetometer VSM), Scanning electron microscopy (SEM), X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The adsorption batch study was carried out to investigate the influence of pH, kinetics, isotherm, and thermodynamics on Cd2+ adsorption. The characterization results demonstrated that the biochar contained iron particles that help in improving the textural properties (i.e., surface area and pore volume), increasing the number of oxygen-containing groups, and forming inner-sphere complexes with oxygen-containing groups. The adsorption study results show that optimum adsorption was achieved under pH 5–6. An increase in initial ion concentration and solution temperature resulted in increased adsorption capacity. Surface modification of biochar using iron oxide for imposing magnetic property allowed for easy separation by external magnet and regeneration. The magnetic biochar composite also showed a higher affinity to Cd2+ than the pristine biochar. The adsorption data fit well with the pseudo-second-order and the Langmuir isotherm, with the maximum adsorption capacity of 47.90 mg/g.

scholarly journals Fabrication of Carboxymethylcellulose/Metal-Organic Framework Beads for Removal of Pb(II) from Aqueous Solution

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 942 ◽  
Author(s):  
Huo-Xi Jin ◽  
Hong Xu ◽  
Nan Wang ◽  
Li-Ye Yang ◽  
Yang-Guang Wang ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Langmuir Isotherm ◽  
Adsorption Equilibrium ◽  
Isotherm Model ◽  
Maximum Adsorption Capacity ◽  
X Ray ◽  
Metal Organic ◽  
Langmuir Isotherm Model

The ability to remove toxic heavy metals, such as Pb(II), from the environment is an important objective from both human-health and ecological perspectives. Herein, we describe the fabrication of a novel carboxymethylcellulose-coated metal organic material (MOF-5–CMC) adsorbent that removed lead ions from aqueous solutions. The adsorption material was characterized by Fourier-transform infrared spectroscopy, X-ray diffractometry, scanning electron microscopy, and X-ray photoelectron spectroscopy. We studied the functions of the contact time, pH, the original concentration of the Pb(II) solution, and adsorption temperature on adsorption capacity. MOF-5–CMC beads exhibit good adsorption performance; the maximum adsorption capacity obtained from the Langmuir isotherm-model is 322.58 mg/g, and the adsorption equilibrium was reached in 120 min at a concentration of 300 mg/L. The adsorption kinetics is well described by pseudo-second-order kinetics, and the adsorption equilibrium data are well fitted to the Langmuir isotherm model (R2 = 0.988). Thermodynamics experiments indicate that the adsorption process is both spontaneous and endothermic. In addition, the adsorbent is reusable. We conclude that MOF-5–CMC is a good adsorbent that can be used to remove Pb(II) from aqueous solutions.

Preparation of Carbon Nanofibers from Polyacrylonitrile Nanofibers by Electrospinning

2011 ◽  
Vol 415-417 ◽  
pp. 642-647
Author(s):  
En Zhong Li ◽  
Da Xiang Yang ◽  
Wei Ling Guo ◽  
Hai Dou Wang ◽  
Bin Shi Xu
Keyword(s):  
Electron Microscope ◽  
Carbon Nanofibers ◽  
Photoelectron Spectroscopy ◽  
Solution Concentration ◽  
Dimethyl Formamide ◽  
Ultrafine Fibers ◽  
X Ray ◽  
Scanning Electron ◽  
Pan Fibers

Ultrafine fibers were electrospun from polyacrylonitrile (PAN)/N,N-dimethyl formamide (DMF) solution as a precursor of carbon nanofibers. The effects of solution concentration, applied voltage and flow rate on preparation and morphologies of electrospun PAN fibers were investigated. Morphologies of the green fibers, stabilized fibers and carbonized fibers were compared by scanning electron microscope (SEM). The diameter of PAN nanofibers is about 450nm and the distribution of diameter is well-proportioned. Characterization of the elements changes of fibers were performed by X-ray photoelectron spectroscopy (XPS).

Magnetic Properties of Bulk Zn0.95-XMnXFe0.05O2 Prepared by Sol-Gel Method and Subsequent Hot Pressing

2011 ◽  
Vol 268-270 ◽  
pp. 356-359 ◽  
Author(s):  
Wen Song Lin ◽  
C. H. Wen ◽  
Liang He
Keyword(s):  
Magnetic Properties ◽  
Photoelectron Spectroscopy ◽  
Raw Materials ◽  
Sol Gel ◽  
Secondary Phase ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Doped Zno

Mn, Fe doped ZnO powders (Zn0.95-xMnxFe0.05O2, x≤0.05) were synthesized by an ameliorated sol-gel method, using Zn(CH3COO)2, Mn(CH3COO)2and FeCl2as the raw materials, with the addition of vitamin C as a kind of chemical reducer. The resulting powder was subsequently compacted under pressure of 10 MPa at the temperature of 873K in vacuum. The crystal structure and magnetic properties of Zn0.95-xMnxFe0.05O2powder and bulk samples have been investigated by X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). X-ray photoelectron spectroscopy (XPS) was used to study chemical valence of manganese, iron and zinc in the samples. The x-ray diffraction (XRD) results showed that Zn0.95-xMnxFe0.05O (x≤0.05) samples were single phase with the ZnO-like wurtzite structure. No secondary phase was found in the XRD spectrum. X-ray photoelectron spectroscopy (XPS) showed that Fe and Mn existed in Zn0.95-xMnxFe0.05O2samples in Fe2+and Mn2+states. The results of VSM experiment proved the room temperature ferromagnetic properties (RTFP) of Mn, Fe co-doped ZnO samples.

scholarly journals Facile Preparation of Rod-like MnO Nanomixtures via Hydrothermal Approach and Highly Efficient Removal of Methylene Blue for Wastewater Treatment

Nanomaterials ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 10 ◽  
Author(s):  
Yuelong Xu ◽  
Bin Ren ◽  
Ran Wang ◽  
Lihui Zhang ◽  
Tifeng Jiao ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Methylene Blue ◽  
Photoelectron Spectroscopy ◽  
Degradation Mechanism ◽  
Dye Adsorption ◽  
Maximum Adsorption Capacity ◽  
X Ray ◽  
Transmission Electron ◽  
Degradation Ratio ◽  
Hydrothermal Approach

In the present study, nanoscale rod-shaped manganese oxide (MnO) mixtures were successfully prepared from graphitic carbon nitride (C3N4) and potassium permanganate (KMnO4) through a hydrothermal method. The as-prepared MnO nanomixtures exhibited high activity in the adsorption and degradation of methylene blue (MB). The as-synthesized products were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), surface area analysis, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Furthermore, the effects of the dose of MnO nanomixtures, pH of the solution, initial concentration of MB, and the temperature of MB removal in dye adsorption and degradation experiments was investigated. The degradation mechanism of MB upon treatment with MnO nanomixtures and H2O2 was studied and discussed. The results showed that a maximum adsorption capacity of 154 mg g−1 was obtained for a 60 mg L−1 MB solution at pH 9.0 and 25 °C, and the highest MB degradation ratio reached 99.8% under the following optimum conditions: 50 mL of MB solution (20 mg L−1) at room temperature and pH ≈ 8.0 with 7 mg of C, N-doped MnO and 0.5 mL of H2O2.

Deposition of gold nanoparticles on organo-kaolinite — Application in electrocatalysis for carbon monoxide oxidation

2011 ◽  
Vol 89 (7) ◽  
pp. 845-853 ◽  
Author(s):  
Sadok Letaief ◽  
Wendy Pell ◽  
Christian Detellier
Keyword(s):  
Carbon Monoxide ◽  
Gold Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
Fine Particles ◽  
Raw Materials ◽  
Carbon Monoxide Oxidation ◽  
Functional Materials ◽  
Metallic State ◽  
Oxidation Reactions ◽  
X Ray

The clay mineral kaolinite was used as support of gold nanoparticles for heterogeneous catalysis of oxidation reactions, particularly of carbon monoxide oxidation. The application of clay minerals in the preparation of new functional materials provides an alternative approach for the use of these abundant raw materials. To improve the physicochemical properties of kaolinite, as well as to ensure a strong immobilization of the adsorbed species, kaolinite was functionalized by grafting 2-amino-2-methyl-1,3-propanediol on the internal and external surfaces of the octahedral sheets by reaction with the aluminol groups. Gold nanoparticles were then deposited on the external surfaces of the fine particles of the functionalized kaolinite. The resulting gold kaolinite nanohybrid material was characterized by various physicochemical techniques. X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, and energy-dispersive X-ray spectrometry confirmed that gold was effectively reduced to the metallic state during adsorption onto the external surfaces of the modified kaolinite. The gold nanoparticles have a narrow size distribution: more than 88% are less than 4 nm in diameter. Gold nanoparticles deposited on kaolinite catalyze the electro-oxidation of carbon monoxide in alkaline solution at room temperature.

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