Synthesis of CaFe2O4-NGO Nanocomposite for Effective Removal of Heavy Metal Ion and Photocatalytic Degradation of Organic Pollutants

This paper reports the successful synthesis of magnetic nanocomposite of calcium ferrite with nitrogen doped graphene oxide (CaFe2O4-NGO) for the effective removal of Pb(II) ions and photocatalytic degradation of congo red and p-nitrophenol. X-ray diffraction (XRD), Fourier transform infrared (FT-IR), transmission electron microscopy (TEM), and scanning electron microscopy-energy dispersive X-ray (SEM-EDX) techniques confirmed the presence of NGO and CaFe2O4 in the nanocomposite. The Mössbauer studies depicted the presence of paramagnetic doublet and sextet due to presence of CaFe2O4 NPs in the nanocomposite. The higher BET surface area in case of CaFe2O4-NGO (52.86 m2/g) as compared to CaFe2O4 NPs (23.45 m2/g) was ascribed to the effective modulation of surface in the presence of NGO. Adsorption followed the Langmuir model with maximum adsorption capacity of 780.5 mg/g for Pb(II) ions. Photoluminescence spectrum of nanocomposite displayed four-fold decrease in the intensity, as compared to ferrite NPs, thus confirming its high light capturing potential and enhanced photocatalytic activity. The presence of NGO in nanocomposite offered an excellent visible light driven photocatalytic performance. The quenching experiments supported ●OH and O2●− radicals as the main reactive species involved in carrying out the catalytic system. The presence of Pb(II) had synergistic effect on photocatalytic degradation of pollutants. This study highlights the synthesis of CaFe2O4-NGO nanocomposite as an efficient adsorbent and photocatalyst for remediating pollutants.

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Hydrothermal Synthesis of Few-Layer and Edge-Rich Cobalt-Doped Molybdenum Selenide/Nitrogenated Graphene Composite and Investigation of Its Electrocatalytic Activity for Hydrogen Evolution Reaction

NANO ◽

10.1142/s1793292016501071 ◽

2016 ◽

Vol 11 (10) ◽

pp. 1650107 ◽

Cited By ~ 3

Author(s):

Ming Ou ◽

Lin Ma ◽

Limei Xu ◽

Zhuomei Yang ◽

Haizhen Li

Keyword(s):

Electron Microscopy ◽

Hydrogen Evolution ◽

Hydrogen Evolution Reaction ◽

Photoelectron Spectroscopy ◽

Hydrothermal Route ◽

X Ray ◽

Graphene Composite ◽

Molybdenum Selenide ◽

Nitrogen Doped Graphene ◽

Doped Graphene

Cobalt-doped MoSe2/nitrogenated graphene composite has been successfully synthesized via a facile hydrothermal route and is investigated as an electrocatalyst for hydrogen evolution reaction (HER). The as-prepared samples are well characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and Raman spectrum. The results reveal that Co-doped MoSe2 nanosheets which are characteristic of few layers (2–4 layers) and abundant exposed active edge sites are well anchored on the nitrogen-doped graphene sheets to constitute robust composites. When evaluated as catalysts for HER, the obtained composites demonstrate superior electrocatalytic activities toward HER.

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Magnetic Nitrogen-doped graphene synthesized from orange peel as highly effective adsorbent for removal of sodium dodecyl benzenesulfonate (SDBS) from aqueous solutions

10.21203/rs.3.rs-391533/v1 ◽

2021 ◽

Author(s):

Arash Khoshnoodfar ◽

Nader Bahramifar ◽

Habibollah Younesi

Keyword(s):

Adsorption Process ◽

Orange Peel ◽

Bet Surface Area ◽

Sodium Dodecylbenzene Sulfonate ◽

Maximum Adsorption Capacity ◽

Order Kinetic ◽

Nitrogen Doped ◽

Nitrogen Doped Graphene ◽

Doped Graphene ◽

Nano Adsorbent

Abstract The purpose of the current research is to investigate the adsorption process behavior of magnetic nitrogen doped graphene (MNG) prepared from the orange peel in the adsorption of sodium dodecylbenzene sulfonate (SDBS) from liquid solution in batch experiments. The characteristics results of VSM, FTIR, SEM, AFM, Raman, elemental analysis and BET surface area analysis revealed the successful synthesis nano adsorbent. The effective factors on adsorption performance were including adsorbent dosage, temperature, contact time, pH and initial concentration of SDBS. The Maximum adsorption capacity for SDBS is computed to be 556 mg/g at 45 ◦C and pH of 3. The adsorption process of SDBS was found that fitted well with the Langmuir isotherm model and pseudo-second-order kinetic equations. Thermodynamic analysis proved the spontaneous and endothermic nature of the adsorption process. Furthermore, the SDBS can be desorbed from the fabricated nano adsorbent by methanol solution with 88 % desorption efficiency and MNG indicated good reusability after five cycles. The finding from this research, propose that the as-synthesized MNG could be an effective adsorbent for water and wastewater treatment because of its convenient process and magnetic separation.

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Poly (N-vinyl Imidazole)/Nitrogen-Doped Graphene Quantum Dot Hydrogel Adsorbent With Remarkable Capability for Metal Ion Removal From Aqueous Systems

10.21203/rs.3.rs-328639/v1 ◽

2021 ◽

Author(s):

Solmaz Massoudi ◽

Massoumeh Bagheri ◽

Maryam Hosseini

Keyword(s):

Adsorption Capacity ◽

Contact Time ◽

Metal Ion ◽

Graphene Quantum Dots ◽

Molar Ratio ◽

Isotherm Models ◽

Maximum Adsorption Capacity ◽

Nitrogen Doped ◽

Nitrogen Doped Graphene ◽

Doped Graphene

Abstract The present work studies the adsorptive removal of cadmium, nickel and chromium ions from an aqueous solution using a highly efficient nanocomposite adsorbent hydrogel. pH-sensitive nanocomposite hydrogels prepared easily by the free radical polymerization of N‑vinyl imidazole (VI) monomer using N, N′- methylene-bis-acrylamide (MBA) and dicationic imidazolium-based (DIL) cross-linkers with molar ratios of monomer/cross-linker in the presence of 0.0, 0.9 and 4.0 wt.% nitrogen doped graphene quantum dots (NGQD). The prepared hydrogel (PVI/NGQD) with higher swelling degree (V-D-G1) with molar ratio of VI/DIL=24 and 4.0 wt.% NGQD was a prominent candidate for adsorption study of three elements (Cd, Ni, and Cr) from the solution. FT-IR, DSC, XRD, SEM, and EDS analysis were used to characterize the structure and the surface morphology of adsorbent before and after the metal ions adsorption. The effects of pH, initial concentration of ions and contact time on the adsorption capacity of the hydrogel were also studied. Adsorption of ions were investigated at pH 1.0, 7.0 and 9.0 and maximum removal efficiencies for Cd(II), Ni(II) and Cr(VI) ions (75%, 94.6% and 70.9%) were achieved at pH=7.0 and optimum ions concentration and contact time of 1000 mg/L, and 40, 40 and 150 min, respectively. The maximum adsorption capacity values of V-D-G1 is found to be 5000, 5000 and 370.370 mg/g for Cd(II), Ni(II) and Cr(VI), respectively. The adsorption data were used to study the adsorption kinetic and isotherm models in which Langmuir model and pseudo-first order model showed the better applicability.

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Efficient Removal of Bisphenol A Using Nitrogen-Doped Graphene-Like Plates from Green Petroleum Coke

Molecules ◽

10.3390/molecules25153543 ◽

2020 ◽

Vol 25 (15) ◽

pp. 3543

Author(s):

Zhipeng Liu ◽

Quanyong Wang ◽

Bei Zhang ◽

Tao Wu ◽

Yujiang Li

Keyword(s):

Bisphenol A ◽

Petroleum Coke ◽

Photoelectron Spectroscopy ◽

Oil Refining ◽

Bet Surface Area ◽

X Ray ◽

Nitrogen Doped ◽

Nitrogen Doped Graphene ◽

Doped Graphene ◽

Green Petroleum Coke

Green petroleum coke, a form of industrial waste produced in the oil-refining process, was used to synthesize nitrogen-doped graphene-like plates (N-GLPs) together with melamine. In this study, characterization and batch experiments were performed to elucidate the interaction mechanism of N-GLPs and bisphenol A (BPA). Structural analysis of N-GLPs, including scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Brunauer-Emmett-Teller (BET), and X-ray photoelectron spectroscopy (XPS), showed an obvious graphene-like structure and successful nitrogen doping. In addition, compared with 8.0 m2/g for green petroleum coke, the BET surface area of N-GLPs markedly increased to 96.6 m2/g. The influences of various factors, including contact time, temperature, and initial pH on BPA removal efficiency were investigated. It was found that 92.0% of BPA was successfully removed by N-GLPs at 50 °C. Based on the adsorption experiments, it was shown that electrostatic attraction, hydrogen bonding, and π-π interaction enhanced the adsorption capacity of N-GLPs for BPA. According to the thermodynamic data, the adsorption process was spontaneous, physical, and endothermic in nature. Therefore, N-GLPs are efficient adsorbent material to remove BPA from wastewater.

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Enhanced Adsorption of Selenium Ions from Aqueous Solution Using Iron Oxide Impregnated Carbon Nanotubes

Bioinorganic Chemistry and Applications ◽

10.1155/2017/4323619 ◽

2017 ◽

Vol 2017 ◽

pp. 1-12 ◽

Cited By ~ 16

Author(s):

Omer Y. Bakather ◽

Ahmad Kayvani Fard ◽

Ihsanullah ◽

Majeda Khraisheh ◽

Mustafa S. Nasser ◽

...

Keyword(s):

Electron Microscopy ◽

Carbon Nanotubes ◽

Iron Oxide ◽

Adsorption Capacity ◽

Langmuir Isotherm ◽

Bet Surface Area ◽

Isotherm Models ◽

Maximum Adsorption Capacity ◽

Adsorption Parameters ◽

X Ray

The aim of this research was to investigate the potential of raw and iron oxide impregnated carbon nanotubes (CNTs) as adsorbents for the removal of selenium (Se) ions from wastewater. The original and modified CNTs with different loadings of Fe2O3 nanoparticles were characterized using high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), X-ray diffractometer (XRD), Brunauer, Emmett, and Teller (BET) surface area analyzer, thermogravimetric analysis (TGA), zeta potential, and energy dispersive X-ray spectroscopy (EDS). The adsorption parameters of the selenium ions from water using raw CNTs and iron oxide impregnated carbon nanotubes (CNT-Fe2O3) were optimized. Total removal of 1 ppm Se ions from water was achieved when 25 mg of CNTs impregnated with 20 wt.% of iron oxide nanoparticles is used. Freundlich and Langmuir isotherm models were used to study the nature of the adsorption process. Pseudo-first and pseudo-second-order models were employed to study the kinetics of selenium ions adsorption onto the surface of iron oxide impregnated CNTs. Maximum adsorption capacity of the Fe2O3 impregnated CNTs, predicted by Langmuir isotherm model, was found to be 111 mg/g. This new finding might revolutionize the adsorption treatment process and application by introducing a new type of nanoadsorbent that has super adsorption capacity towards Se ions.

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Bimetallic Pd-Co Nanoparticles Supported on Nitrogen-Doped Reduced Graphene Oxide as Efficient Electrocatalysts for Formic Acid Electrooxidation

Catalysts ◽

10.3390/catal11080910 ◽

2021 ◽

Vol 11 (8) ◽

pp. 910

Author(s):

SK Safdar Hossain ◽

Mohammad Mudassir Alwi ◽

Junaid Saleem ◽

Hussain Taj Al-Hashem ◽

Gordon McKay ◽

...

Keyword(s):

Electron Microscopy ◽

Graphene Oxide ◽

Formic Acid ◽

Reduced Graphene Oxide ◽

X Ray ◽

Nitrogen Doped ◽

Reduced Graphene ◽

Steady State Current ◽

Nitrogen Doped Graphene ◽

Doped Graphene

In this work, bimetallic PdxCoy nanoparticles supported on nitrogen-doped reduced graphene oxide catalysts were synthesized and tested for formic acid oxidation as potentially efficient and durable electrocatalysts. Graphene oxide was nitrogen doped through hydrothermal chemical reduction with urea as a nitrogen source. The PdxCoy nanoparticles were deposited on the nitrogen-doped graphene oxide support using the impregnation-reduction method with sodium borohydride as a reducing agent and sodium citrate dihydrate as a stabilizing agent. The structural features, such as phases, composition, oxidation states, and particle sizes, of the nanoparticles were characterized using X-ray diffraction, transmission electron microscopy, scanning electron microscopy–energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. The Pd nanoparticle sizes in Pd1Co1/N-rGO, Pd/N-rGO, and Pd1Co1/CNT were 3.5, 12.51, and 4.62 nm, respectively. The electrochemical performance of the catalysts was determined by CO stripping, cyclic voltammetry, and chronoamperometry. Pd1Co1/N-rGO showed the highest mass activity of 4833.12 mA–1 mg Pd, which was twice that of Pd1Co1/CNT. Moreover, Pd1Co1/N-rGO showed a steady-state current density of 700 mA–1 mg Pd after 5000 s in chronoamperometry carried out at +0.35 V. Apart from the well-known bifunctional effect of Co, nitrogen-doped graphene contributed to the performance enhancement of the Pd1Co1/N-rGO catalyst.

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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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Fly Ash Coated with Magnetic Materials: Improved Adsorbent for Cu (II) Removal from Wastewater

Materials ◽

10.3390/ma14010063 ◽

2020 ◽

Vol 14 (1) ◽

pp. 63

Author(s):

Maria Harja ◽

Gabriela Buema ◽

Nicoleta Lupu ◽

Horia Chiriac ◽

Dumitru Daniel Herea ◽

...

Keyword(s):

Fly Ash ◽

Adsorption Capacity ◽

Copper Ions ◽

Synthetic Wastewater ◽

Bet Surface Area ◽

Isotherm Models ◽

Batch Adsorption ◽

Maximum Adsorption Capacity ◽

Copper Adsorption ◽

X Ray

Fly ash/magnetite material was used for the adsorption of copper ions from synthetic wastewater. The obtained material was characterized by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET) surface area, and vibrating sample magnetometer (VSM). Batch adsorption experiments were employed in order to investigate the effects of adsorbent dose, initial Cu (II) concentration and contact time over adsorption efficiency. The experimental isotherms were modeled using Langmuir (four types of its linearization), Freundlich, Temkin, and Harkins–Jura isotherm models. The fits of the results are estimated according to the Langmuir isotherm, with a maximum adsorption capacity of 17.39 mg/g. The pseudo-second-order model was able to describe kinetic results. The data obtained throughout the study prove that this novel material represents a potential low-cost adsorbent for copper adsorption with improved adsorption capacity and magnetic separation capability compared with raw fly ash.

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Magnetically Recyclable Wool Keratin Modified Magnetite Powders for Efficient Removal of Cu2+ Ions from Aqueous Solutions

Nanomaterials ◽

10.3390/nano11051068 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1068

Author(s):

Xinyue Zhang ◽

Yani Guo ◽

Wenjun Li ◽

Jinyuan Zhang ◽

Hailiang Wu ◽

...

Keyword(s):

Electron Microscopy ◽

Aqueous Solutions ◽

Adsorption Capacity ◽

Surface Area ◽

Ion Concentration ◽

Bet Surface Area ◽

Chemical Compositions ◽

Ion Adsorption ◽

X Ray ◽

Wool Keratin

The treatment of wastewater containing heavy metals and the utilization of wool waste are very important for the sustainable development of textile mills. In this study, the wool keratin modified magnetite (Fe3O4) powders were fabricated by using wool waste via a co-precipitation technique for removal of Cu2+ ions from aqueous solutions. The morphology, chemical compositions, crystal structure, microstructure, magnetism properties, organic content, and specific surface area of as-fabricated powders were systematically characterized by various techniques including field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM), thermogravimetric (TG) analysis, and Brunauer–Emmett–Teller (BET) surface area analyzer. The effects of experimental parameters such as the volume of wool keratin hydrolysate, the dosage of powder, the initial Cu2+ ion concentration, and the pH value of solution on the adsorption capacity of Cu2+ ions by the powders were examined. The experimental results indicated that the Cu2+ ion adsorption performance of the wool keratin modified Fe3O4 powders exhibited much better than that of the chitosan modified ones with a maximum Cu2+ adsorption capacity of 27.4 mg/g under favorable conditions (0.05 g powders; 50 mL of 40 mg/L CuSO4; pH 5; temperature 293 K). The high adsorption capacity towards Cu2+ ions on the wool keratin modified Fe3O4 powders was primarily because of the strong surface complexation of –COOH and –NH2 functional groups of wool keratins with Cu2+ ions. The Cu2+ ion adsorption process on the wool keratin modified Fe3O4 powders followed the Temkin adsorption isotherm model and the intraparticle diffusion and pseudo-second-order adsorption kinetic models. After Cu2+ ion removal, the wool keratin modified Fe3O4 powders were easily separated using a magnet from aqueous solution and efficiently regenerated using 0.5 M ethylene diamine tetraacetic acid (EDTA)-H2SO4 eluting. The wool keratin modified Fe3O4 powders possessed good regenerative performance after five cycles. This study provided a feasible way to utilize waste wool textiles for preparing magnetic biomass-based adsorbents for the removal of heavy metal ions from aqueous solutions.

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

Nanomaterials ◽

10.3390/nano9010010 ◽

2018 ◽

Vol 9 (1) ◽

pp. 10 ◽

Cited By ~ 37

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.

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