Adsorption Mechanism Study of Magnetic EDTA-Chitosan on Cu (II) Ions of Solution

2014 ◽  
Vol 937 ◽  
pp. 218-223
Author(s):  
Run Hua Qin ◽  
Feng Sheng Li ◽  
Wei Jiang ◽  
Ling Yun Hao
Keyword(s):  
Photoelectron Spectroscopy ◽  
Active Sites ◽  
Adsorption Mechanism ◽  
Influence Factor ◽  
Adsorption Property ◽  
Chelating Agent ◽  
Magnetic Adsorbent ◽  
Mechanism Study ◽  
X Ray ◽  
Adsorption Mechanisms

A novel magnetic adsorbent, magnetic EDTA/chitosan nanobeads was synthesized. The adsorption mechanisms of magnetic EDTA/chitosan nanobeads for removal of Cu (II) ions from aqueous solution were investigated in this paper. The interaction mechanisms of Cu2+ adsorption onto magnetic EDTA/chitosan nanobeads and active sites were interpreted by fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis. Uniting the analysis results of FTIR and XPS, the functional groups of participating in chelating were confirmed, and the results indicated that Cu2+ adsorption was mainly through interactions with electron donating atom N and O. This adsorption property was similar to N·O-type chelating agent and the adsorption mechanism was put forward. This work was very significant to control adsorption influence factor and improve adsorption capacity of magnetic EDTA-chitosan nanobeads, and then succeed to apply to magnetic adsorption fields.

scholarly journals Preparation of GO/MIL-101(Fe,Cu) composite and its adsorption mechanisms for phosphate in aqueous solution

2021 ◽  
Author(s):  
You Wu ◽  
Zuannian Liu ◽  
Bakhtari Mohammad Fahim ◽  
Junnan Luo
Keyword(s):  
Adsorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Adsorption Mechanism ◽  
Nitrogen Adsorption ◽  
Adsorption Properties ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adsorption Mechanisms ◽  
Adsorption Desorption

Abstract In this study, MIL-101(Fe), MIL-101(Fe,Cu), and Graphene Oxide (GO) /MIL-101(Fe,Cu) were synthesized to compose a novel sorbent. The adsorption properties of these three MOFs-based composites were compared toward the removal of phosphate. Furthermore, the influencing factors including reaction time, pH, temperature and initial concentration on the adsorption capacity of phosphate on these materials as well as the reusability of the material were discussed. The structure of fabricated materials and the removal mechanism of phosphate on the composite material were analyzed by Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), nitrogen adsorption-desorption analysis and zeta potential. The results show that the maximum adsorption capacity of phosphate by the composite GO/MIL-101(Fe,Cu)-2% was 204.60 mg·g− 1, which is higher than that of MIL-101(Fe,Cu) and MIL-101(Fe). likewise the specific surface area of GO/MIL-101(Fe,Cu)-2% is 778.11 m2/g is higher than that of MIL-101(Fe,Cu) and MIL-101(Fe),which are 747.75 and 510.66m2/g respectively. The adsorption mechanism of phosphate is electrostatic attraction, form coordination bonds and hydrogen bonds. The fabricated material is a promising adsorbent for the removal of phosphate with good reusability.

Synthesis of Novel g-C3N4/NH2-MIL-88B(Fe) Composite Photocatalysis for Efficient Ciprofloxacin Degradation Under Simulated Sunlight Irradiation

NANO ◽  
2021 ◽  
pp. 2150063
Author(s):  
Jungang Yi ◽  
Kun Wu ◽  
Huadong Wu ◽  
Jia Guo ◽  
Linfeng Zhang ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Adsorption Property ◽  
Catalytic Performance ◽  
Step Method ◽  
Area Formula ◽  
Aquatic Life ◽  
X Ray ◽  
Transmission Electron ◽  
Uniform Dispersion ◽  
Composite Photocatalysts

The presence of the antibiotics in the wastewater has posed a huge risk to aquatic life and human health. It is a great significance to develop an effective technology to treat the antibiotics-containing wastewater. In this study, a series of g-C3N4/NH2-MIL-88B(Fe) composite photocatalysts are synthesized through a simple one-step method. The structure and optical properties of prepared photocatalysts are detected by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV–Vis absorption spectra (UV–Vis DRS), photoluminescence (PL) spectroscopy and transient photocurrent techniques, respectively. FESEM and TEM show that MOF is uniformly dispersed in petaloid g-C3N4. The uniform dispersion of Fe-MOFs in the heterojunction composites increases the specific surface area ([Formula: see text] of g-C3N4, which results in a great adsorption property for the nanocomposite. The capture experiment shows that [Formula: see text]O[Formula: see text] and h[Formula: see text] are the main active substances in ciprofloxacin (CIP) degradation. These prepared composite photocatalysts exhibit excellent CIP photodegradation activity under visibly light irradiation with an apparent rate constant of 0.0127[Formula: see text]min[Formula: see text] (3.74 times as the rate of single component). The remarkable catalytic performance can be ascribed to the fact that the g-C3N4/NH2-MIL-88B(Fe) heterojunction inhibits the recombination of photoinduced electron–hole pairs and improved the visible light absorption.

scholarly journals Capping Agent Effect on Pd-Supported Nanoparticles in the Hydrogenation of Furfural

Catalysts ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 11 ◽  
Author(s):  
Shahram Alijani ◽  
Sofia Capelli ◽  
Stefano Cattaneo ◽  
Marco Schiavoni ◽  
Claudio Evangelisti ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Active Sites ◽  
Catalytic Performance ◽  
Shielding Effect ◽  
Capping Agents ◽  
X Ray ◽  
Supported Nanoparticles ◽  
Liquid Phase Hydrogenation ◽  
Diallyldimethylammonium Chloride ◽  
Transmission Electron

The catalytic performance of a series of 1 wt % Pd/C catalysts prepared by the sol-immobilization method has been studied in the liquid-phase hydrogenation of furfural. The temperature range studied was 25–75 °C, keeping the H2 pressure constant at 5 bar. The effect of the catalyst preparation using different capping agents containing oxygen or nitrogen groups was assessed. Polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), and poly (diallyldimethylammonium chloride) (PDDA) were chosen. The catalysts were characterized by ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The characterization data suggest that the different capping agents affected the initial activity of the catalysts by adjusting the available Pd surface sites, without producing a significant change in the Pd particle size. The different activity of the three catalysts followed the trend: PdPVA/C > PdPDDA/C > PdPVP/C. In terms of selectivity to furfuryl alcohol, the opposite trend has been observed: PdPVP/C > PdPDDA/C > PdPVA/C. The different reactivity has been ascribed to the different shielding effect of the three ligands used; they influence the adsorption of the reactant on Pd active sites.

scholarly journals Nitrogen-Doped Sponge Ni Fibers as Highly Efficient Electrocatalysts for Oxygen Evolution Reaction

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Kaili Zhang ◽  
Xinhui Xia ◽  
Shengjue Deng ◽  
Yu Zhong ◽  
Dong Xie ◽  
...  
Keyword(s):  
Oxygen Evolution ◽  
Photoelectron Spectroscopy ◽  
Oxygen Evolution Reaction ◽  
Active Sites ◽  
High Performance ◽  
Active Phase ◽  
X Ray ◽  
Highly Active ◽  
N Doping ◽  
Energy Conversion Devices

Abstract Controllable synthesis of highly active micro/nanostructured metal electrocatalysts for oxygen evolution reaction (OER) is a particularly significant and challenging target. Herein, we report a 3D porous sponge-like Ni material, prepared by a facile hydrothermal method and consisting of cross-linked micro/nanofibers, as an integrated binder-free OER electrocatalyst. To further enhance the electrocatalytic performance, an N-doping strategy is applied to obtain N-doped sponge Ni (N-SN) for the first time, via NH3 annealing. Due to the combination of the unique conductive sponge structure and N doping, the as-obtained N-SN material shows improved conductivity and a higher number of active sites, resulting in enhanced OER performance and excellent stability. Remarkably, N-SN exhibits a low overpotential of 365 mV at 100 mA cm−2 and an extremely small Tafel slope of 33 mV dec−1, as well as superior long-term stability, outperforming unmodified sponge Ni. Importantly, the combination of X-ray photoelectron spectroscopy and near-edge X-ray adsorption fine structure analyses shows that γ-NiOOH is the surface-active phase for OER. Therefore, the combination of conductive sponge structure and N-doping modification opens a new avenue for fabricating new types of high-performance electrodes with application in electrochemical energy conversion devices.

Pulsed Laser Deposition in a Zinc Alloy Corrosion Study

2003 ◽  
Vol 780 ◽  
Author(s):  
R. Guerrero-Penalva ◽  
M.H. Farías ◽  
L. Cota-Araiza
Keyword(s):  
Pulsed Laser Deposition ◽  
Photoelectron Spectroscopy ◽  
Active Sites ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Reactive Element ◽  
General Mechanism ◽  
Zinc Alloy ◽  
Reactive Element Effect ◽  
X Ray

AbstractA significant improvement in corrosion resistance of the protecting oxide of alloys has been observed when adding small amounts of reactive elements, such as yttrium, this effect has been called reactive element effect (REE). The general mechanism of the REE has not been determined yet. In this work, we study a growing of a yttrium oxide film and its interaction with the phases η and α that constitutes the alloy Zn-22Al-2Cu named ZinalcoTM The alloy's surface was coated by a pulsed laser deposition technique. The deposit is controlled and characterized by x-ray photoelectron spectroscopy. The mechanism by which the reactive element produce its effects in this alloy is explained by the preferential interaction among the active sites related to the zinc rich phase and enhancing aluminum movement toward the surface where it is oxidized and the protection film formed.

The Mechanism Research of Collector and Hemimorphite

2014 ◽  
Vol 1073-1076 ◽  
pp. 2163-2167
Author(s):  
Kang Kang Li ◽  
Xiao Lin Zhang ◽  
Shi Ming Cao ◽  
Dian Wen Liu
Keyword(s):  
Zinc Oxide ◽  
Photoelectron Spectroscopy ◽  
Density Functional ◽  
Adsorption Mechanism ◽  
Efficient Utilization ◽  
Functional Theory ◽  
X Ray ◽  
The Density Functional Theory ◽  
Mechanism Research ◽  
Drying Up

As the zinc minerals of easy separation drying up, efficient utilization of refractory zinc oxide ores is getting more and more attention, especially for siliceous zinc oxide ore is quite difficult to separate, and it is a challenge for worldwide mineral processing industry. This article mainly used the density functional theory and X-ray photoelectron spectroscopy to study the adsorption mechanism of amine collectors on hemimorphite, when the composite activator was working.

Mesoporous Co–B amorphous alloy films with enhanced catalytic efficiency prepared from a mixed-surfactant solution

2009 ◽  
Vol 24 (11) ◽  
pp. 3300-3307 ◽  
Author(s):  
Hui Li ◽  
Jun Liu ◽  
Haixia Yang ◽  
Hexing Li
Keyword(s):  
Amorphous Alloy ◽  
Photoelectron Spectroscopy ◽  
Active Sites ◽  
Chemical Reduction ◽  
Surfactant Solution ◽  
Mesoporous Structure ◽  
Mixed Surfactant ◽  
Alloy Films ◽  
X Ray ◽  
Electron Micrography

Co–B films were synthesized through the solvent evaporation-assisted chemical reduction method by using a mixed-surfactant solution containing Span 40 and (1S)-(+)-10-camphorsulfonic acid. With the characterization of x-ray diffraction, selected-area electron diffraction, x-ray photoelectron spectroscopy, scanning electron micrography, and transmission electron micrography, the resulting Co–B films were identified to be amorphous alloys with mesoporous structure. The synergistic effect of two kinds of surfactants is essential for the formation of mesoporous structure. During liquid-phase cinnamaldehyde hydrogenation to cinnamyl alcohol, the mesoporous Co–B amorphous alloy films exhibited a much higher activity and better selectivity than the solid Co–B nanoparticles prepared by direct reduction of cobalt ions with borohydride. The enhanced activity is attributed to both the mesoporous and the film structure, which provides more Co active sites for the adsorption and diffusion of reactant molecules. The improved selectivity may be related to the difference in surface curvature.

scholarly journals Study of oxygen evolution reaction on thermally prepared xPtOy-(100-x)IrO2 electrodes

2020 ◽  
Vol 10 (4) ◽  
pp. 347-360
Author(s):  
Ollo Kambiré ◽  
Lemeyonouin A. G. Pohan ◽  
Konan H. Kondro ◽  
Lassiné Ouattara
Keyword(s):  
Surface Area ◽  
Oxygen Evolution ◽  
Photoelectron Spectroscopy ◽  
Oxygen Evolution Reaction ◽  
Active Sites ◽  
Platinum Oxide ◽  
Basic Medium ◽  
X Ray ◽  
Tafel Slopes ◽  
Ohmic Drop

The mixed coupled xPtOy-(100-x)IrO2 electrodes (x = 0, 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100) were thermally prepared at 450 °C on titanium supports. The prepared electrodes were firstly physically characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Afterwards, electrochemical characteri­zations were performed by voltammetric (cyclic and linear) methods in different electrolyte media (KOH and HClO4). It is shown that the prepared electrodes are composed by both PtOy (platinum and platinum oxide) and IrO2 (iridium dioxide). For xPtOy-(100-x)IrO2 electrodes having higher content of IrO2, more surface cracks and pores are formed, defining a higher surface area with more active sites. Higher surface area due to presence of both PtOy and IrO2, is for xPtOy-(100-x)IrO2 electrodes in 1 M KOH solution confirmed by cyclic voltammetry at potentials of the oxide layer region. For all prepared electrodes, voltammetric charges were found higher than for PtOy, while the highest voltammetric charge is observed for the mixed 40PtOy-60IrO2 (x = 40) electrode. The Tafel slopes for oxygen evolution reaction (OER) in either basic (0.1 M KOH) or acid (0.1 M HClO4) media were determined from measured linear voltammograms corrected for the ohmic drop. The values of Tafel slopes for OER at PtOy, 90PtOy-10IrO2 and IrO2 in basic medium are 122, 55 and 40 mV dec-1, respectively. For other mixed electrodes, Tafel slopes of 40 mV dec-1 were obtained. Although proceeding by different OER mechanism, similar values of Tafel slopes were obtained in acid medium, i.e., Tafel slopes of 120, 60 and 39 mV dec-1 were obtained for PtOy, 90PtOy-10IrO2 and IrO2, and 40 mV dec-1 for other mixed electrodes. The analysis of Tafel slope values showed that OER is more rapid on coupled mixed electrodes than on pure PtOy. For mixed xPtOy-(100-x)IrO2 electrodes, OER is more rapid when the molar percent of PtOy meets the following condition: 0 ˂ x ≤ 80. This study also showed that the mixed coupled electrodes are more electro­cata­lytically active for OER than either PtOy or IrO2 in these two media. 

scholarly journals Isotherm and Kinetic Modeling of Strontium Adsorption on Graphene Oxide

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2780
Author(s):  
Abdulrahman Abu-Nada ◽  
Ahmed Abdala ◽  
Gordon McKay
Keyword(s):  
Graphene Oxide ◽  
Aqueous Solutions ◽  
Functional Groups ◽  
Photoelectron Spectroscopy ◽  
Active Sites ◽  
Nitrogen Adsorption ◽  
Order Kinetic ◽  
X Ray ◽  
Oxygen Functional Groups ◽  
Bet Analysis

In this study, graphene oxide (GO) was synthesized using Hummers method. The synthesized GO was characterized using field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), Fourier transformed infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and Brunauer–Emmett–Teller (BET) nitrogen adsorption. The analyses confirmed the presence of oxygen functional groups (C=O and C-O-C) on the GO surface. These oxygen functional groups act as active sites in the adsorption Sr (II). The BET analysis revealed the surface area of GO of 232 m2/g with a pore volume of 0.40 cm3/g. The synthesized GO was used as an adsorbent for removing Sr (II) from aqueous solutions. The adsorption equilibrium and kinetic results were consistent with the Langmuir isotherm model and the pseudo-second-order kinetic model. A maximum strontium adsorption capacity of 131.4 mg/g was achieved. The results show that the GO has an excellent adsorption capability for removing Sr (II) from aqueous solutions and potential use in wastewater treatment applications.

scholarly journals Coexistence and Adsorption Properties of Heavy Metals by Polypropylene Microplastics

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Tingyu Fan ◽  
Jie Zhao ◽  
Yingxiang Chen ◽  
Miao Wang ◽  
Xingming Wang ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Photoelectron Spectroscopy ◽  
Adsorption Mechanism ◽  
Adsorption Process ◽  
Adsorption Properties ◽  
Primary Sources ◽  
Freundlich Model ◽  
X Ray ◽  
Sources Of Pollution ◽  
Best Fitting

Plastic particles with a diameter of 5 mm or less are called microplastics. Microplastics are one of the primary sources of pollution in the environment. It has been proven that microplastics are also carriers of heavy metals, but there are few studies on their adsorption mechanism. In this study, the adsorption of Pb, Cu, Cd, and Zn by polypropylene (PP) microplastics was analyzed and discussed. The morphology of PP was observed by scanning electron microscopy (SEM), the surface elemental composition of PP was determined by X-ray photoelectron spectroscopy (XPS), and the functional groups of PP were analyzed by Fourier transform infrared spectroscopy (FTIR). The results showed that the adsorption behavior of microplastics to different heavy metals could be balanced in 32 hours. Kinetics experiments showed that the adsorption process could be fitted well by a two-stage dynamic model, and the adsorption of Pb and Cu by PP is greater than that of Cd and Zn. The Freundlich model has the best fitting effect on Pb for the adsorption isothermal results. The Langmuir model showed that the process is favorable for adsorption. The adsorption of mixed heavy metals by microplastics showed that when the concentration of the mixed adsorption mass was low, the presence of a coexistence system promoted the adsorption of Zn and Cu by microplastics. With an increasing concentration, the adsorption of 4 heavy metals by microplastics is inhibited.

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