Eco-Friendly Ferrimagnetic-Humic Acid Nanocomposites as Superior Magnetic Adsorbents

Recyclable, cheap, eco-friendly, and efficient adsorbent materials are very important for the removal of pollution. In this work, we report the design and implementation of ferrimagnetic-humic acid nanocomposites as superior magnetic adsorbent for heavy metals. Ferrimagnetic and ferrimagnetic-humic acid nanocomposite particles with different morphologies were prepared using the coprecipitation method and hydrothermal synthesis method, respectively. The results show that the morphology of the nanoparticles prepared by the coprecipitation method is more uniform and the size is smaller than that by the hydrothermal synthesis method. Adsorption experiments show that the ferrimagnetic-humic acid nanoparticles prepared by the coprecipitation method has high sorption capacity for cadmium, and the maximum adsorption capacity is about 763 μg/g. At the same time, magnetic technology can be used to realize the recycling of ferrimagnetic-humic acid adsorbents.

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Synthesis of graphene/Fe3O4 nano composites

Science and Technology Development Journal ◽

10.32508/stdj.v18i2.1182 ◽

2015 ◽

Vol 18 (2) ◽

pp. 166-176

Author(s):

Trinh Thi Tuyet Ho ◽

Tam Thanh Mai ◽

Huy Duc Ha

Keyword(s):

Aqueous Media ◽

Synthesis Method ◽

Environmental Water ◽

Water Soluble ◽

Coprecipitation Method ◽

Nano Particles ◽

Magnetic Characteristics ◽

Maximum Adsorption Capacity ◽

Freundlich Isotherms ◽

Structure Morphology

In this work, we have demonstrated a coprecipitation method combined in situreduction method for the synthesis of graphene/magnetite nanocomposites (MRGO) and for its application in dye removal from aqueous media for the environmental water treatment. The Fe3O4 nano particles were synthesized by coprecipitation method, and water-soluble chitosan was used as surface-active substances to help the dispersion stability of Fe3O4 nano particles. In addition, graphene oxide (GO) was reduced into graphene by Lascorbic acid. The structure, morphology, and magnetic characteristics of the nanosized composite were investigated by analysis methods such as XRD, FTIR, TEM, SEM, VSM, TGA ... The synthesis method is efficient, scalable, green, and controllable. Fe3O4 nanoparticles in size of 9-15 nm were homogeneously dispersed onto graphene sheets. The saturated magnetization of MRGO is 41 emu/g. Adsorption isotherm of Rhodamine (RhB) onto RGO/Fe3O4 nanocomposites were studied in a batch system. The experimental results showed that the adsorption data were much fitted with Langmuir adsorption isotherms than with Freundlich isotherms. The maximum adsorption capacity of RhB on MRGO is 38 mg/g.

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Synthesis of Silver-Impregnated Magnetite Mesoporous Silica Composites for Removing Iodide in Aqueous Solution

Toxics ◽

10.3390/toxics9080175 ◽

2021 ◽

Vol 9 (8) ◽

pp. 175

Author(s):

Sang-Eun Jo ◽

Jung-Weon Choi ◽

Sang-June Choi

Keyword(s):

Aqueous Solution ◽

Langmuir Isotherm ◽

High Surface ◽

High Surface Area ◽

High Capacity ◽

Maximum Adsorption Capacity ◽

Initial Contact ◽

Order Kinetic ◽

Sorption Ability ◽

High Sorption

Mag@silica-Ag composite has a high sorption ability for I− in aqueous solution due to its high surface area and strong affinity for the studied anion. The material adsorbed I− rapidly during the initial contact time (in 45 min, η = 80%) and reached adsorption equilibrium after 2 h. Moreover, mag@silica-Ag proved to selectively remove I− from a mixture of Cl−, NO3− and I−. The adsorption behavior fitted the Langmuir isotherm perfectly and the pseudo-second-order kinetic model. Based on the Langmuir isotherm, the maximum adsorption capacity of mag@silica-Ag was 0.82 mmol/g, which is significantly higher than previously developed adsorbents. This study introduces a practical application of a high-capacity adsorbent in removing radioactive I− from wastewaters.

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Eco-environmental preparation of magnetic activated carbon modified with 3-aminopropyltrimethoxysilane (APTMS) from sawdust waste as a novel efficient adsorbent for humic acid removal: Characterisation, modelling, optimisation and equilibrium studies

International Journal of Environmental & Analytical Chemistry ◽

10.1080/03067319.2021.1928096 ◽

2021 ◽

pp. 1-21

Author(s):

Mehrnaz Hosseinzehi ◽

Mohammad Hassan Ehrampoush ◽

Fatemeh Tamaddon ◽

Mehdi Mokhtari ◽

Arash Dalvand

Keyword(s):

Activated Carbon ◽

Humic Acid ◽

Equilibrium Studies ◽

Magnetic Activated Carbon ◽

Efficient Adsorbent

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

Molecules ◽

10.3390/molecules26030661 ◽

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.

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Synthesis and characterization of Cu(OH)2-NWs-PVA-AC Nano-composite and its use as an efficient adsorbent for removal of methylene blue

Scientific Reports ◽

10.1038/s41598-021-84797-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Sivarama Krishna Lakkaboyana ◽

Khantong Soontarapa ◽

Nabel Kalel Asmel ◽

Vinay Kumar ◽

Ravi Kumar Marella ◽

...

Keyword(s):

Methylene Blue ◽

Kinetic Models ◽

Batch Reactor ◽

Maximum Adsorption Capacity ◽

Nano Composite ◽

Adsorption Processes ◽

Intra Particle Diffusion ◽

Short Time ◽

Efficient Adsorbent

AbstractThe present study focused on the synthesis of copper hydroxide nanowires decorated on activated carbon (Cu(OH)2-NWs-PVA-AC). The obtained Cu(OH)2-NWs-PVA-AC Nano-composite was distinguished by XRD, SEM, EDX, BET, FTIR and XPS respectively. Besides, different variables such as solution pH, and initial dye concentration, contact time, and temperature were performed on the adsorption efficiency of MB in a small batch reactor. Further, the experimental results are analyzed by various kinetic models via PFO, PSO, intra-particle diffusion and Elovich models, and the results revealed that among the kinetic models, PSO shows more suitability. In addition, different adsorption isotherms were applied to the obtained experimental data and found that Langmuir–Freundlich and Langmuir isotherm were best fits with the maximum adsorption capacity of 139.9 and 107.6 mg/g, respectively. The Nano-composite has outstanding MB removal efficiency of 94–98.5% with a span of 10 min. and decent adsorption of about 98.5% at a pH of 10. Thermodynamic constants like Gibbs free energy, entropy, and enthalpy were analyzed from the temperature reliance. The results reveal the adsorption processes are spontaneous and exothermic in nature. The high negative value of ΔG° (− 44.11 to − 48.86 kJ/mol) and a low negative value of ΔH° (− 28.96 kJ/mol) show the feasibility and exothermic nature of the adsorption process. The synthesized dye was found to be an efficient adsorbent for the potential removal of cationic dye (methylene blue) from wastewater within a short time.

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Sustainable Chromium (VI) Removal from Contaminated Groundwater Using Nano-Magnetite-Modified Biochar via Rapid Microwave Synthesis

Molecules ◽

10.3390/molecules26010103 ◽

2020 ◽

Vol 26 (1) ◽

pp. 103

Author(s):

Xiaoming Song ◽

Yuewen Zhang ◽

Nan Cao ◽

Dong Sun ◽

Zhipeng Zhang ◽

...

Keyword(s):

Synthesis Method ◽

Microwave Treatment ◽

Contaminated Groundwater ◽

Maximum Adsorption Capacity ◽

Intraparticle Diffusion Model ◽

Adsorption Mechanisms ◽

Chromium Vi ◽

Modified Biochar ◽

Pseudo Second Order ◽

Nano Fe3o4

This study developed a nano-magnetite-modified biochar material (m-biochar) using a simple and rapid in situ synthesis method via microwave treatment, and systematically investigated the removal capability and mechanism of chromium (VI) by this m-biochar from contaminated groundwater. The m-biochar was fabricated from reed residues and magnetically modified by nano-Fe3O4. The results from scanning electron microscopy (SEM) and X-ray diffraction (XRD) characterisations confirmed the successful doping of nano-Fe3O4 on the biochar with an improved porous structure. The synthesised m-biochar exhibited significantly higher maximum adsorption capacity of 9.92 mg/g compared with that (8.03 mg/g) of the pristine biochar. The adsorption kinetics followed the pseudo-second-order model and the intraparticle diffusion model, which indicated that the overall adsorption rate of Cr(VI) was governed by the processes of chemical adsorption, liquid film diffusion and intramolecular diffusion. The increasing of the pH from 3 to 11 significantly affected the Cr(VI) adsorption, where the capabilities decreased from 9.92 mg/g to 0.435 mg/g and 8.03 mg/g to 0.095 mg/g for the m-biochar and pristine biochar, respectively. Moreover, the adsorption mechanisms of Cr(VI) by m-biochar were evaluated and confirmed to include the pathways of electrostatic adsorption, reduction and complexation. This study highlighted an effective synthesis method to prepare a superior Cr(VI) adsorbent, which could contribute to the effective remediation of heavy metal contaminations in the groundwater.

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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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Microwave-Assisted vs. Conventional Hydrothermal Synthesis of MoS2 Nanosheets: Application towards Hydrogen Evolution Reaction

Crystals ◽

10.3390/cryst10111040 ◽

2020 ◽

Vol 10 (11) ◽

pp. 1040 ◽

Cited By ~ 1

Author(s):

Getachew Solomon ◽

Raffaello Mazzaro ◽

Vittorio Morandi ◽

Isabella Concina ◽

Alberto Vomiero

Keyword(s):

Hydrothermal Synthesis ◽

Hydrothermal Method ◽

Hydrogen Evolution ◽

Hydrogen Evolution Reaction ◽

Current Density ◽

Crystal Morphology ◽

Synthesis Method ◽

Synthesis Methods ◽

Mos2 Nanosheets ◽

Microwave Assisted

Molybdenum sulfide (MoS2) has emerged as a promising catalyst for hydrogen evolution applications. The synthesis method mainly employed is a conventional hydrothermal method. This method requires a longer time compared to other methods such as microwave synthesis methods. There is a lack of comparison of the two synthesis methods in terms of crystal morphology and its electrochemical activities. In this work, MoS2 nanosheets are synthesized using both hydrothermal (HT-MoS2) and advanced microwave methods (MW-MoS2), their crystal morphology, and catalytical efficiency towards hydrogen evolution reaction (HER) were compared. MoS2 nanosheet is obtained using microwave-assisted synthesis in a very short time (30 min) compared to the 24 h hydrothermal synthesis method. Both methods produce thin and aggregated nanosheets. However, the nanosheets synthesized by the microwave method have a less crumpled structure and smoother edges compared to the hydrothermal method. The as-prepared nanosheets are tested and used as a catalyst for hydrogen evolution results in nearly similar electrocatalytic performance. Experimental results showed that: HT-MoS2 displays a current density of 10 mA/cm2 at overpotential (−280 mV) compared to MW-MoS2 which requires −320 mV to produce a similar current density, suggesting that the HT-MoS2 more active towards hydrogen evolutions reaction.

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