scholarly journals Synthesis, characterization and adsorption capacity of lead(II) ions of Fe3O4/C core-shell structure materials

2021 ◽  
Vol 10 (2) ◽  
pp. 43-48
Author(s):  
Dang Le Hai ◽  
Trang Luu Thu ◽  
Hoang Tran Vinh ◽  
Doanh Vu Viet ◽  
Thu Le Dieu ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Magnetite Nanoparticles ◽  
Shell Structure ◽  
Adsorption Process ◽  
Langmuir Model ◽  
Core Shell ◽  
Order Model ◽  
Pseudo Second Order ◽  
Core Shell Structure ◽  
Model Expression

Core shell magnetite nanoparticles (Fe3O4@C) as adsorbent for lead ions from aqueous solution were synthesized. The characteristics of the modified materials were analysed. It could also be shown that the adsorption isotherms were well described by the Langmuir model. The kinetic of the adsorption process was found to follow the pseudo-second-order model expression. Thermodynamic studies indicated that the adsorption process was feasible, spontaneous and endothermic.

scholarly journals Synthesis Fe3O4/Talc nanocomposite by coprecipition-ultrasonication method and advances in hexavalent chromium removal from aqueous solution

2020 ◽  
Vol 38 (9-10) ◽  
pp. 483-501
Author(s):  
Nguyen Thi Huong ◽  
Nguyen Ngoc Son ◽  
Vo Hoang Phuong ◽  
Cong Tien Dung ◽  
Pham Thi Mai Huong ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
Low Cost ◽  
Batch Experiments ◽  
X Ray Diffraction ◽  
Order Model ◽  
X Ray ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Langmuir And Freundlich Equations

The Fe3O4/Talc nanocomposite was synthesized by the coprecipitation-ultrasonication method. The reaction was carried out under a inert gas environment. The nanoparticles were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), fourier-transform infrared spectroscopy (FT-IR) and vibrating sample magnetometry techniques (VSM), the surface area of the nanoparticles was determined to be 77.92 m2/g by Brunauer-Emmett-Teller method (BET). The kinetic data showed that the adsorption process fitted with the pseudo-second order model. Batch experiments were carried out to determine the adsorption kinetics and mechanisms of Cr(VI) by Fe3O4/Talc nanocomposite. The adsorption process was found to be highly pH-dependent, which made the material selectively adsorb these metals from aqueous solution. The isotherms of adsorption were also studied using Langmuir and Freundlich equations in linear forms. It is found that the Langmuir equation showed better linear correlation with the experimental data than the Freundlich. The thermodynamics of Cr(VI) adsorption onto the Fe3O4/Talc nanocomposite indicated that the adsorption was exothermic. The reusability study has proven that Fe3O4/Talc nanocomposite can be employed as a low-cost and easy to separate.

Preparation of bio-based magnetic adsorbent and application for efficient removal of Cd(II) from water

2018 ◽  
Vol 77 (5) ◽  
pp. 1313-1323 ◽  
Author(s):  
Jianjun Zhou ◽  
Xionghui Ji ◽  
Xiaohui Zhou ◽  
Jialin Ren ◽  
Yaochi Liu
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
Low Cost ◽  
Maximum Adsorption Capacity ◽  
Magnetic Adsorbent ◽  
Order Model ◽  
Efficient Removal ◽  
Adsorption Ability ◽  
Adsorption Sites ◽  
Pseudo Second Order

Abstract A novel magnetic bio-adsorbent (MCIA) was developed, characterized and tested for its Cd(II) removal from aqueous solution. MCIA could be easily separated from the solution after equilibrium adsorption due to its super-paramagnetic property. The functional and magnetic bio-material was an attractive adsorbent for the removal of Cd(II) from aqueous solution owing to the abundant adsorption sites, amino-group and oxygen-containing groups on the surface of Cyclosorus interruptus. The experimental results indicated that the MCIA exhibited excellent adsorption ability and the adsorption process was spontaneous and endothermic. The adsorption isotherm was consistent with the Langmuir model. The adsorption kinetic fitted the pseudo-second-order model very well. The maximum adsorption capacity of Cd(II) onto MCIA was 40.8, 49.4, 54.6 and 56.6 mg/g at 293, 303, 313 and 323 K, respectively. And the MCIA exhibited an excellent reusability and impressive regeneration. Therefore, MCIA could serve as a sustainable, efficient and low-cost magnetic adsorbent for Cd(II) removal from aqueous solution.

Surface Engineering of Magnetite Nanoparticles by Plant Protein: Investigation into Magnetic Properties

2016 ◽  
Vol 11 ◽  
pp. 38-44 ◽  
Author(s):  
Amlan Kumar Das ◽  
Avinash Marwal ◽  
Vikram Pareek ◽  
Yagya Joshi ◽  
Apoorva
Keyword(s):  
Magnetite Nanoparticles ◽  
Shell Structure ◽  
Colloidal Stability ◽  
Surface Engineering ◽  
Thermo Gravimetric Analysis ◽  
Magnetic Behaviour ◽  
Plant Protein ◽  
Core Shell ◽  
Gravimetric Analysis ◽  
Core Shell Structure

The surface of the magnetite nanoparticles has been engineered by the proteins available in the leaf extract of Datura inoxia. Fourier Transform Infrared (FTIR) study and by thermo gravimetric analysis (TGA) confirms the bonding between metal ions and the amide carbonyl group preset in the plant protein confirming the formation of core-shell structure. The plant protein coated magnetic Fe3O4 nanoparticles under investigation have an average size of about 14 nm (˂20nm). The isothermal magnetization curve of the ferrofluid appears in S-like sigmoid shape showing soft nonhysteretic magnetic behaviour at room temperature. The saturation magnetization (MS), remanent magnetization (MR), squareness (MR/MS) and coercivity value (HC) increased with decreasing temperature from 300 K to 10 K. The increment of magnetization (45 to 53 emu/gm) might be due to the decrease in thermal energy while the enhancement of coercivity (0-208 Oe) is attributed to the exchange interaction at the interface between the ferromagnetic (Fe3O4) and diamagnetic surface layer of protein on the nanocrystalline magnetite. The magnetization value is much smaller in comparison with the bulk magnetite (92emu/g) due to surface spin disorder also approves core-shell structure of diamagnetic protein layer on the surface. The results show the ease of the synthesis to reinforce the colloidal stability where the super paramagnetic behaviour has been found to be restored. The core-shell moiety could play an important role in biological systems as a means of storing Fe+3 for an organism.

Facile synthesis of chitosan nanoparticle-modified MnO2 nanoflakes for ultrafast adsorption of Pb(II) from aqueous solution

2016 ◽  
Vol 17 (1) ◽  
pp. 32-38 ◽  
Author(s):  
Tianli Han ◽  
Xiaoman Zhang ◽  
Xiangqian Fu ◽  
Jinyun Liu
Keyword(s):  
Aqueous Solution ◽  
Ph Value ◽  
Langmuir Model ◽  
Maximum Adsorption Capacity ◽  
Order Model ◽  
Facile Synthesis ◽  
Adsorption Sites ◽  
Chitosan Nanoparticle ◽  
Pseudo Second Order ◽  
Potential Strategy

Chitosan nanoparticle (CS NP)-modified MnO2 nanoflakes were presented as a novel adsorbent for fast adsorption of Pb(II) from aqueous solution. Loading dense CS NPs onto mono-dispersive flower-like MnO2 nanostructures reduces the overlap of CS during adsorption, and thus improves the contact of functional adsorption sites on the surface of MnO2 nanoflakes with heavy metal ions. The results show that the removal efficiency of the nanoadsorbents reaches up to 93% in 3 min for Pb(II). In addition, the maximum adsorption capacity, effects of adsorbent dosage and pH value, and the reusability were investigated. The kinetic process and adsorption isotherm fit well with the pseudo-second-order model and Langmuir model, respectively. These findings provide a potential strategy to address the overlap issue of some common nanoadsorbents.

scholarly journals A turn-on fluorescent sensor based on coffee-grounds carbon dots for the detection of sodium cyclamate

2021 ◽  
Author(s):  
Junzhe Chen ◽  
Haiying Du ◽  
Yifeng Xu ◽  
Boyu Ma ◽  
Zhihong Zheng ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Quantum Dots ◽  
Shell Structure ◽  
Sulfamic Acid ◽  
Carbon Quantum Dots ◽  
Core Shell ◽  
Hydroxyl Groups ◽  
Coffee Grounds ◽  
Core Shell Structure ◽  
Sodium Cyclamate

Abstract Carbon quantum dots (CQDs) were synthesized by coffee-grounds as carbon source under hydrothermal carbonization treatment for the first time. The obtained CQDs showed a strong emission at the wavelength of 460 nm, with an optimum excitation of 370 nm, and enrichment of the surface functional groups(-OH, -NH2). Sodium cyclamate in an aqueous solution and the CQDs could form a core-shell structure by hydrogen-bonding and van der waals bonding to enhance the fluorescent emission. Cyclohexyl sulfamate forms cyclohexyl sulfamate in an aqueous solution and then undergoes dehydration and condensation with the hydroxyl groups on the carbon quantum dots, and finally sodium cyclamate forms a core-shell structure around the carbon quantum dots.环己基氨基磺酸盐在水溶液中形成环己基氨基磺酸盐，然后与碳量子点上的羟基进行脱水和缩合，最后环甜酸钠在碳量子点周围形成核-壳结构。Cyclohexyl sulfamate form a cyclohexyl sulfamic acid in an aqueous solution followed by dehydration condensation with hydroxyl groups on the carbon quantum dots, cyclamate final core-shell structure is formed in the peripheral carbon quantum dot,

scholarly journals A Mild and Facile Synthesis of Amino Functionalized CoFe2O4@SiO2 for Hg(II) Removal

Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 673 ◽  
Author(s):  
Xi Wang ◽  
Zhenzong Zhang ◽  
Yuhao Zhao ◽  
Kai Xia ◽  
Yongfu Guo ◽  
...  
Keyword(s):  
Shell Structure ◽  
Core Shell ◽  
Order Kinetic ◽  
Preparation Time ◽  
Application Performance ◽  
Operational Conditions ◽  
Monolayer Adsorption ◽  
Pseudo Second Order ◽  
Core Shell Structure ◽  
Key Steps

To avoid the dangerous operational conditions, shorten the preparation time, and improve the adsorption performance of amino-functionalized nanomagnetic materials with a core–shell structure, a magnetic nanocomposite of CoFe2O4@SiO2 was successfully functionalized with amino group (−NH2) through a mild and facile hydrothermal method without the use of any toxic or harmful solvents at a relatively low temperature. The preparation time of the key steps of amino functionalization was shortened from 30 h to about 10 h. The core-shell structure and successful grafting were confirmed by various means. The amino-functionalized CoFe2O4@SiO2 was used for the removal mercury (Hg(II)), a heavy metal, and exhibited excellent magnetic properties and a high Langmuir adsorption capacity of 149.3 mg Hg(II)/g. The adsorption of Hg(II) onto CoFe2O4@SiO2–NH2 followed the pseudo-second-order kinetic equation and Langmuir model. The thermodynamic data showed that the Hg(II) adsorption process was achieved through spontaneous exothermic and monolayer adsorption with electrostatic adsorption and chemisorption. In addition, the as-prepared CoFe2O4@SiO2–NH2 nanoparticles had a good reusable value, good application performance and stability, and can provide a mild and facile way to remove heavy metals from aqueous solution.

Sorption of Uranium (VI) From Aqueous Solution Using Nanomagnetite Particles; Singly and Coated With Humic Acid

2021 ◽  
Author(s):  
Ismail Mohamed Ahmed ◽  
Aly A. Helal ◽  
Rasha Gamal ◽  
Salah aboEinien ◽  
Abdullah A. Helal
Keyword(s):  
Aqueous Solution ◽  
Humic Acid ◽  
Magnetite Nanoparticles ◽  
Kinetic Data ◽  
Contact Time ◽  
Organic Coating ◽  
Langmuir Model ◽  
Sorption Kinetic ◽  
Maximum Capacity ◽  
Pseudo Second Order

Abstract Magnetite nanoparticles (Fe3O4) and humic acid coated magnetite nanoparticles (Fe3O4/HA) were investigated for the removal of U(VI) from aqueous solution. Batch sorption experiments were studied as a function contact time, adsorbent mass, U(VI) concentration and pH. The sorption kinetic data follow the pseudo-second order while the isotherms are found to obey Langmuir model with maximum capacity (Qmax) of 230, 196 mg/g for Fe3O4 and Fe3O4/HA, respectively. The study reveals that humic acid decreases the sorption capacity due to the formation of a polyanionic organic coating and thus altering the surface properties of the particles and reduces the magnetite aggregation and stabilizes the magnetite suspension.

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