Fenton Degradation of Ofloxacin Using a Montmorillonite-Fe3O4 Composite

In this work, FeM composites consisting of montmorillonite and variable amounts of Fe3O4 were successfully synthesized via a facile co-precipitation process. They were characterized using X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscope (TEM), N2 adsorption-desorption, and Fourier transform infrared spectroscopy (FT-IR) techniques to explain the effect of Fe3O4 content on the physicochemical properties of the Fe3O4-montmorillonite (FeM) composites. The FeM composites were subsequently used as heterogeneous Fenton catalysts to activate green oxidant (H2O2) for the subsequent degradation of ofloxacin (OFL) antibiotic. The efficiency of the FeM composites was studied by varying various parameters of Fe3O4 loading on montmorillonite, catalyst dosage, initial solution pH, initial OFL concentration, different oxidants, H2O2 dosage, reaction temperature, inorganic salts, and solar irradiation. Under the conditions of 0.75 g/L FeM-10, 5 mL/L H2O2, and natural pH, almost 81% of 50 mg/L of OFL was removed within 120 min in the dark, while total organic carbon (TOC) reduction was about 56%. Moreover, the FeM-10 composite maintained high efficiency and was stable even after four continuous cycles, making it a promising candidate in real wastewater remediation.

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Fenton Degradation of Ofloxacin Using a Montmorillonite–Fe3O4 Composite

Catalysts ◽

10.3390/catal11020177 ◽

2021 ◽

Vol 11 (2) ◽

pp. 177

Author(s):

Alamri Rahmah Dhahawi Ahmad ◽

Saifullahi Shehu Imam ◽

Wen Da Oh ◽

Rohana Adnan

Keyword(s):

Electron Microscope ◽

Photoelectron Spectroscopy ◽

Solar Irradiation ◽

Precipitation Process ◽

Solution Ph ◽

Significant Drop ◽

X Ray ◽

Subsequent Degradation ◽

Co Precipitation ◽

Adsorption Desorption

In this work, FeM composites consisting of montmorillonite and variable amounts of Fe3O4 were successfully synthesized via a facile co-precipitation process. They were characterized using X-ray photoelectron spectroscopy (XPS), a field emission scanning electron microscope (FESEM), energy-dispersive X-ray spectroscopy (EDX), a transmission electron microscope (TEM), N2 adsorption–desorption, and Fourier transform infrared spectroscopy (FTIR) techniques to explain the effect of Fe3O4 content on the physicochemical properties of the Fe3O4–montmorillonite (FeM) composites. The FeM composites were subsequently used as heterogeneous Fenton catalysts to activate green oxidant (H2O2) for the subsequent degradation of ofloxacin (OFL) antibiotic. The efficiency of the FeM composites was studied by varying various parameters of Fe3O4 loading on montmorillonite, catalyst dosage, initial solution pH, initial OFL concentration, different oxidants, H2O2 dosage, reaction temperature, inorganic salts, and solar irradiation. Under the conditions of 0.75 g/L FeM-10, 5 mL/L H2O2, and natural pH, almost 81% of 50 mg/L of OFL was degraded within 120 min in the dark, while total organic carbon (TOC) reduction was about 56%. Although FeM composites could be a promising heterogeneous catalyst for the activation of H2O2 to degrade organic pollutants, including OFL antibiotic, the FeM-10 composite shows a significant drop in efficiency after five cycles, which indicates that more studies to improve this weakness should be conducted.

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Preparation and characterization of iron-copper binary oxide and its effective removal of antimony(III) from aqueous solution

Water Science & Technology ◽

10.2166/wst.2016.219 ◽

2016 ◽

Vol 74 (2) ◽

pp. 393-401 ◽

Cited By ~ 3

Author(s):

Yongchao Li ◽

Bing Geng ◽

Xiaoxian Hu ◽

Bozhi Ren ◽

Andrew S. Hursthouse

Keyword(s):

Aqueous Solution ◽

Photoelectron Spectroscopy ◽

Binary Oxide ◽

Molar Ratio ◽

Precipitation Process ◽

Maximum Adsorption Capacity ◽

Solution Ph ◽

X Ray ◽

Freundlich Adsorption Isotherm ◽

Co Precipitation

An Fe-Cu binary oxide was fabricated through a simple co-precipitation process, and was used to remove Sb(III) from aqueous solution. X-ray diffraction, scanning electron microscopy, energy dispersive X-ray and N2 adsorption–desorption measurements demonstrated that the Fe-Cu binary oxide consisted of poorly ordered ferrihydrite and CuO, and its specific surface area was higher than both iron oxide and copper oxide. A comparative test indicated that Fe/Cu molar ratio of prepared binary oxide greatly influenced Sb(III) removal and the optimum Fe/Cu molar ratio was about 3/1. Moreover, a maximum adsorption capacity of 209.23 mg Sb(III)/g Fe-Cu binary oxide at pH 5.0 was obtained. The removal of Sb(III) by Fe-Cu binary oxide followed the Freundlich adsorption isotherm and the pseudo-second-order kinetics in the batch study. The removal of Sb(III) was not sensitive to solution pH. In addition, the release of Fe and Cu ions to water was very low when the pH was greater than 6.0. X-ray photoelectron spectroscopy analysis confirmed that the Sb(III) adsorbed on the surface was not oxidized to Sb(V).

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Differentiating Nanomaghemite and Nanomagnetite and Discussing Their Importance in Arsenic and Lead Removal from Contaminated Effluents: A Critical Review

Nanomaterials ◽

10.3390/nano11092310 ◽

2021 ◽

Vol 11 (9) ◽

pp. 2310

Author(s):

Juan A. Ramos-Guivar ◽

Diego A. Flores-Cano ◽

Edson Caetano Passamani

Keyword(s):

Heavy Metal ◽

Iron Oxides ◽

Photoelectron Spectroscopy ◽

High Efficiency ◽

Magnetic Circular Dichroism ◽

Cost Evaluation ◽

Precipitation Method ◽

Lead Removal ◽

X Ray ◽

Co Precipitation

Arsenic and lead heavy metals are polluting agents still present in water bodies, including surface (lake, river) and underground waters; consequently, the development of new adsorbents is necessary to uptake these metals with high efficiency, quick and clean removal procedures. Magnetic nanoparticles, prepared with iron-oxides, are excellent candidates to achieve this goal due to their ecofriendly features, high catalytic response, specific surface area, and pulling magnetic response that favors an easy removal. In particular, nanomagnetite and maghemite are often found as the core and primary materials regarding magnetic nanoadsorbents. However, these phases show interesting distinct physical properties (especially in their surface magnetic properties) but are not often studied regarding correlations between the surface properties and adsorption applications, for instance. Thus, in this review, we summarize the main characteristics of the co-precipitation and thermal decomposition methods used to prepare the nano-iron-oxides, being the co-precipitation method most promising for scaling up processes. We specifically highlight the main differences between both nano-oxide species based on conventional techniques, such as X-ray diffraction, zero and in-field Mössbauer spectroscopy, X-ray photoelectron spectroscopy, X-ray absorption spectroscopy, and X-ray magnetic circular dichroism, the latter two techniques performed with synchrotron light. Therefore, we classify the most recent magnetic nanoadsorbents found in the literature for arsenic and lead removal, discussing in detail their advantages and limitations based on various physicochemical parameters, such as temperature, competitive and coexisting ion effects, i.e., considering the simultaneous adsorption removal (heavy metal–heavy metal competition and heavy metal–organic removal), initial concentration, magnetic adsorbent dose, adsorption mechanism based on pH and zeta potential, and real water adsorption experiments. We also discuss the regeneration/recycling properties, after-adsorption physicochemical properties, and the cost evaluation of these magnetic nanoadsorbents, which are important issues, but less discussed in the literature.

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Phosphate removal from aqueous solution by Fe-La binary (hydr)oxides: A study of batch experiments and mechanisms

10.21203/rs.3.rs-396802/v1 ◽

2021 ◽

Author(s):

Haijing Duan ◽

Lin Zhang ◽

Yu-long Wang ◽

Yanhong Liu ◽

Yangyang Wang

Keyword(s):

Photoelectron Spectroscopy ◽

High Efficiency ◽

Ph Value ◽

Phosphate Removal ◽

Bet Surface Area ◽

Precipitation Method ◽

Batch Experiments ◽

Exchange Reactions ◽

X Ray ◽

Co Precipitation

Abstract In this study, Fe-La binary (hydr)oxides were prepared by a co-precipitation method for phosphate removal. Various techniques, including secondary electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), powder X-ray diffraction (p-XRD) and Brunauer-Emmett-Teller (BET) surface area analysis, were employed to characterize the synthesized Fe-La binary (hydr)oxides. Batch experiments indicated that the performance of phosphate removal by Fe-La binary (hydr)oxides was excellent and increased with increasing La contents. The kinetics study showed that the adsorption was rapid and described better by the pseudo-second-order equation. The maximum adsorption capacities of Fe/La 3:1, Fe/La 1:1 and Fe/La 1:3 binary (hydr)oxides at pH 4.0 calculated by Langmuir model were 49.02, 69.44 and 136.99 mg/g, respectively. The uptake of phosphate was highly affected by solution pH and significantly reduced with the increase of pH value. The analyses of p-XRD, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) suggested that the predominant mechanisms of phosphate removal involved surface hydroxyl exchange reactions and co-precipitation of released La3+ and phosphate ions, which resulted into the formation of amorphous phase of rhabdophane (LaPO4∙0.5H2O). The results show great potential for the application on the treatment of phosphate decontamination for their high efficiency of phosphate removal.

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Synthesis and Characterization of Fe0.8Mn0.2Fe2O4 Ferrite Nanoparticle with High Saturation Magnetization via the Surfactant Assisted Co-Precipitation

Nanomaterials ◽

10.3390/nano11040876 ◽

2021 ◽

Vol 11 (4) ◽

pp. 876

Author(s):

Kornkanok Rotjanasuworapong ◽

Wanchai Lerdwijitjarud ◽

Anuvat Sirivat

Keyword(s):

Electron Microscope ◽

Saturation Magnetization ◽

Photoelectron Spectroscopy ◽

Sodium Dodecyl ◽

Ferrite Nanoparticles ◽

Ferromagnetic Behavior ◽

X Ray ◽

Ferrite Nanoparticle ◽

Co Precipitation ◽

Surfactant Assisted

Manganese ferrite nanoparticles (MnFe2O4) were synthesized via surfactant-assisted co-precipitation, where sodium dodecyl sulfate (SDS) was used as the template to control particle size at various SDS concentrations. The substitutions of iron (II) (Fe2+) into the MnFe2O4 ferrite nanoparticles were carried out to obtain Fe(1–x)MnxFe2O4, with various Mn2+: Fe2+ molar ratios. The synthesized ferrite nanoparticles were characterized by the Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric analyzer (TGA), X-ray diffractometer (XRD), energy dispersive X-ray (EDX), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), transmission electron microscope (TEM), two-point probe, and vibrating sample magnetometer (VSM) techniques. The experimental Mn:Fe mole ratios of the Fe(1−x)MnxFe2O4 ferrite nanoparticles were verified to be in agreement with the theoretical values. The synthesized MnFe2O4 and Fe(1−x)MnxFe2O4 ferrite nanoparticles were of mixed spinel structures, with average spherical particle sizes between 17–22 nm, whereas the magnetite ferrite nanoparticles (Fe3O4) were of the inverse spinel structure. They showed soft ferromagnetic behavior. The synthesized Fe0.8Mn0.2Fe2O4 ferrite nanoparticle possessed the highest saturation magnetization of 88 emu/g relative to previously reported work to date.

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Improvement of microwave absorption properties of polyester coatings using NiFe2O4, X-doped g-C3N4 (X = S, P, and O), and MTiO3 (M = Fe, Mg, and Zn) nanofillers

Scientific Reports ◽

10.1038/s41598-021-98666-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Somayeh Solgi ◽

Mir Saeed Seyed Dorraji ◽

Seyyedeh Fatemeh Hosseini ◽

Mohammad Hossein Rasoulifard ◽

Ismael Hajimiri ◽

...

Keyword(s):

Electron Microscope ◽

Microwave Absorption ◽

High Efficiency ◽

Sol Gel ◽

X Ray ◽

Transmission Electron ◽

Effective Performance ◽

The Matrix ◽

Co Precipitation ◽

Electromagnetic Pollution

AbstractIn recent decades, to reduce electromagnetic pollution, scientists focus on finding new microwave absorbers with effective performance, thin thickness, and broad bandwidth. In this work, the nanoparticles of NiFe2O4, X-doped g-C3N4 (M = S, P, and O), and MTiO3 (M = Fe, Mg, and Zn) were successfully synthesized using co-precipitation, specific heat program, and semi-wet sol–gel methods, respectively. The synthesized nanoparticles were utilized as absorption agents and polyester resin as the matrix. Morphology, particle size, crystal structure, and chemical composition of the prepared nanocomposites were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffractometer (XRD), and energy dispersive X-Ray analysis (EDX), respectively. The microwave absorption performance of the coatings was also investigated by a vector network analyzer (VNA). Moreover, the effect of different parameters on the performance of absorbent coatings was studied by the Taguchi method and optimized to achieve an optimal absorbent. The results showed that the optimal nanocomposite has the reflectance loss (RL) less than − 30 dB (equal to absorption > 99%) at a high-frequency range (8–12 GHz) and 1 mm thickness. Furthermore, the addition of such novel nanoparticles to absorbents resulted in high values of attenuation constant (more than 200 dB/m) at the X-band. Therefore, the polyester coating filled with ZnTiO3, O-doped g-C3N4, and NiFe2O4 nanofillers can be considered a high-efficiency and low-density absorber.

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Crystalline/Amorphous Blend Identification from Cobalt Adsorption by Layered Double Hydroxides

Materials ◽

10.3390/ma11091706 ◽

2018 ◽

Vol 11 (9) ◽

pp. 1706 ◽

Cited By ~ 5

Author(s):

Lin Chi ◽

Zheng Wang ◽

Yuan Sun ◽

Shuang Lu ◽

Yan Yao

Keyword(s):

Photoelectron Spectroscopy ◽

Inductively Coupled Plasma ◽

Ph Value ◽

Precipitation Process ◽

X Ray ◽

Adsorption Mechanisms ◽

Inductively Coupled ◽

Co Precipitation ◽

Double Hydroxide ◽

Double Hydroxides

In this study, the adsorption behavior of CaAl-Cl layered double hydroxide (CaAl-Cl-LDH) with a controlled pH value (pH = 6) on Co(II) ions ([Co] = 8 mM) is investigated. The comprehensively accepted mechanism of cobalt adsorption on LDH is considered to be co-precipitation, and the final adsorbed products are normally crystalline Co-LDH. One unanticipated finding is that crystalline/amorphous blends are found in the X-ray diffraction (XRD) pattern of Co-adsorbed LDH. To shed light on the adsorption products and the mechanisms in the adsorption process of Co(II) in an aqueous solution by CaAl-Cl-LDH, a series of testing methods including Fourier-transform infrared spectroscopy (FT-IR), Scanning electron microscope (SEM), High-resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma (ICP) are applied to clarify the interaction between cobalt and CaAl-Cl-LDH. According to the comprehensive analysis, the formation of the crystalline/amorphous blends corresponds to two adsorption mechanisms. The crystalline phases are identified as Co6Al2CO3(OH)16·4H2O, which is attributed to the co-precipitation process occurring in the interaction between Co(II) and CaAl-Cl-LDH. The formation of the amorphous phases is due to surface complexation on amorphous Al(OH)3 hydrolyzed from CaAl-Cl-LDH.

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Synthesis of Ce1−xPdxO2−δ Solid Solution in Molten Nitrate

Catalysts ◽

10.3390/catal10060640 ◽

2020 ◽

Vol 10 (6) ◽

pp. 640

Author(s):

Hideaki Sasaki ◽

Keisuke Sakamoto ◽

Masami Mori ◽

Tatsuaki Sakamoto

Keyword(s):

Electron Microscopy ◽

Solid Solution ◽

Solid Solutions ◽

Photoelectron Spectroscopy ◽

Synthesis Method ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Co Precipitation ◽

Ionic States

CeO2-based solid solutions in which Pd partially substitutes for Ce attract considerable attention, owing to their high catalytic performances. In this study, the solid solution (Ce1−xPdxO2−δ) with a high Pd content (x ~ 0.2) was synthesized through co-precipitation under oxidative conditions using molten nitrate, and its structure and thermal decomposition were examined. The characteristics of the solid solution, such as the change in a lattice constant, inhibition of sintering, and ionic states, were examined using X-ray diffraction (XRD), scanning electron microscopy–energy-dispersive X-ray spectroscopy (SEM−EDS), transmission electron microscopy (TEM)−EDS, and X-ray photoelectron spectroscopy (XPS). The synthesis method proposed in this study appears suitable for the easy preparation of CeO2 solid solutions with a high Pd content.

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Preparation and Characterization of Visible-Light-Activated Fe-N Co-Doped TiO2and Its Photocatalytic Inactivation Effect on Leukemia Tumors

International Journal of Photoenergy ◽

10.1155/2012/631435 ◽

2012 ◽

Vol 2012 ◽

pp. 1-9 ◽

Cited By ~ 8

Author(s):

Kangqiang Huang ◽

Li Chen ◽

Jianwen Xiong ◽

Meixiang Liao

Keyword(s):

Electron Microscope ◽

Photoelectron Spectroscopy ◽

Sol Gel ◽

Light Therapy ◽

Cell Counting ◽

Visible Absorption ◽

X Ray ◽

Photocatalytic Inactivation ◽

Inactivation Efficiency ◽

Co Doped

The Fe-N co-doped TiO2nanocomposites were synthesized by a sol-gel method and characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), ultraviolet-visible absorption spectroscopy (UV-vis) and X-ray photoelectron spectroscopy (XPS). Then the photocatalytic inactivation of Fe-N-doped TiO2on leukemia tumors was investigated by using Cell Counting Kit-8 (CCK-8) assay. Additionally, the ultrastructural morphology and apoptotic percentage of treated cells were also studied. The experimental results showed that the growth of leukemic HL60 cells was significantly inhibited in groups treated with TiO2nanoparticles and the photocatalytic activity of Fe-N-TiO2was significantly higher than that of Fe-TiO2and N-TiO2, indicating that the photocatalytic efficiency could be effectively enhanced by the modification of Fe-N. Furthermore, when 2 wt% Fe-N-TiO2nanocomposites at a final concentration of 200 μg/mL were used, the inactivation efficiency of 78.5% was achieved after 30-minute light therapy.

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Preparation of Carbon Nanofibers from Polyacrylonitrile Nanofibers by Electrospinning

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.415-417.642 ◽

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).

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