scholarly journals Removal of F− from Water Using Templated Mesoporous Carbon Modified with Hydrated Zirconium Oxide

2020 ◽  
Vol 6 (1) ◽  
pp. 13
Author(s):  
Tomoya Takada
Keyword(s):  
Pore Size ◽  
Photoelectron Spectroscopy ◽  
Zirconium Oxide ◽  
Mesoporous Carbon ◽  
Zirconium Oxychloride ◽  
Fluoride Anion ◽  
Mesoporous Carbons ◽  
X Ray ◽  
Hydrated Zirconium ◽  
Hydrolysis Of

Three types of MgO-templated mesoporous carbon possessing different specific surface area and pore size distribution were modified with hydrated zirconium oxide (ZrO2·xH2O) to prepare fluoride anion (F−) adsorbents. ZrO2·xH2O was synthesized through the auto-hydrolysis of zirconium oxychloride (ZrOCl2) in water under the coexistence of mesoporous carbon. X-ray diffractometry (XRD) and X-ray photoelectron spectroscopy (XPS) indicated that the mesoporous carbon surfaces were coated with mainly amorphous ZrO2·xH2O. Capabilities of aqueous F− removal of the prepared adsorbents and the unmodified mesoporous carbons were compared. The F− uptake by the prepared adsorbents was larger than that observed using unmodified carbons, indicating that the F− adsorption capacity was improved through the ZrO2·xH2O coating. Moreover, the adsorption capability was found to depend on the pore size of the mesoporous carbons. The F− uptake decreased as pH of F− solution increased. Protonation and deprotonation of ZrO2 were found to affect the F− adsorption.

A Label-Free Electrochemical Aptasensor for the Rapid Detection of Tetracycline Based on Ordered Mesoporous Carbon–Fe3O4

2018 ◽  
Vol 71 (3) ◽  
pp. 170 ◽  
Author(s):  
Xuejia Zhan ◽  
Guangzhi Hu ◽  
Thomas Wagberg ◽  
Dongwei Zhang ◽  
Pei Zhou
Keyword(s):  
Photoelectron Spectroscopy ◽  
Mesoporous Carbon ◽  
Physical Adsorption ◽  
Differential Pulse ◽  
Ordered Mesoporous Carbon ◽  
Label Free ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ordered Mesoporous ◽  
Modification Procedure

A novel aptasensor based on a tetracycline (TET) aptamer immobilized by physical adsorption on an ordered mesoporous carbon–Fe3O4 (OMC-Fe3O4)-modified screen-printed electrode surface was successfully fabricated. OMC-Fe3O4 was characterized by scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The modification procedure of the aptasensor was characterized by cyclic voltammetry. Interaction between the TET aptamer and target was determined by differential pulse voltammetry. Under optimal conditions, the proposed aptasensor exhibited good electrochemical sensitivity to TET in a concentration range of 5 nM to 10 μM, with a detection limit of 0.8 nM (S/N = 3). This aptasensor exhibited satisfactory specificity, reproducibility, and stability.

scholarly journals Copper microsphere hybrid mesoporous carbon as matrix for preparation of shape-stabilized phase change materials with improved thermal properties

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yi Liu ◽  
Yan Chen ◽  
Junwei Zhang ◽  
Junkai Gao ◽  
Zhi Han
Keyword(s):  
Thermal Properties ◽  
Phase Change ◽  
Photoelectron Spectroscopy ◽  
Mesoporous Carbon ◽  
Phase Change Materials ◽  
Copper Ions ◽  
Thermal Constant ◽  
Step Method ◽  
Scanning Calorimetry ◽  
X Ray

Abstract Copper microsphere hybrid mesoporous carbon (MPC-Cu) was synthesized by the pyrolysis of polydopamine microspheres doped with copper ions that were prepared using a novel, facile and simple one-step method of dopamine biomimetic polymerization and copper ion adsorption. The resulting MPC-Cu was then used as a supporter for polyethylene glycol (PEG) to synthesize shape-stabilized phase change materials (PEG/MPC-Cu) with enhanced thermal properties. PEG/MPC-Cu was studied by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, differential scanning calorimetry and thermal constant analysis. The results demonstrated that the thermal conductivity of PEG/MPC-Cu was 0.502 W/(m K), which increased by 100% compared to pure PEG [0.251 W/(m K)]. The melting enthalpy of PEG/MPC-Cu was 95.98 J/g, indicating that PEG/MPC-Cu is a promising candidate for future thermal energy storage applications. In addition, the characterization results suggested that PEG-MPC-Cu possessed high thermal stability. Therefore, the method developed in this paper for preparing shape-stabilized phase change materials with improved thermal properties has substantial engineering application prospects.

scholarly journals Preparation of MgO-Templated N-Doped Mesoporous Carbons from Polyvinylpyrrolidone: Effect of Heating Temperature on Pore Size Distribution

2019 ◽  
Vol 5 (2) ◽  
pp. 15
Author(s):  
Tomoya Takada ◽  
Mayu Kurihara
Keyword(s):  
Pore Size ◽  
Nitrogen Content ◽  
Acid Treatment ◽  
Heating Temperature ◽  
Inert Atmosphere ◽  
Raw Material ◽  
Mesoporous Carbons ◽  
X Ray Diffraction ◽  
X Ray ◽  
Templated Carbon

Magnesium oxide (MgO)-templated nitrogen (N)-doped mesoporous carbons were prepared by using polyvinylpyrrolidone (PVP) as a raw material and magnesium lactate (Mglac) as a precursor for the MgO template to examine the influence of heating temperature and MgO precursor (magnesium acetate was used in similar previous studies) on the pore size and nitrogen content. The MgO-templated carbon was obtained by heating the PVP/Mglac mixture in an inert atmosphere followed by an acid treatment for MgO removal. The mesopore size of the carbons was approximately 4 nm regardless of heating temperature, corresponding to the crystallite size of the MgO template estimated via X-ray diffraction. This indicates that the mesopore of approximately 4 nm was generated using the MgO template. However, larger pores were also found to exist. This result indicates that the larger pores generated through processes other than the MgO templating, likely the thermal decomposition of PVP, are contained in the templated carbon. The volume of the larger pores and the specific surface area increased with increasing heating temperature. The nitrogen content of the carbon decreased as the heating temperature was increased, but it was found to be irrelevant to the MgO precursor.

Hydrothermal Synthesis and Characterization of Phosphor Doped Tetragonal Zirconia Nanocrystallites

2011 ◽  
Vol 197-198 ◽  
pp. 846-852
Author(s):  
Jian Jun Yin ◽  
Tao Wang ◽  
Wei Jing Xing
Keyword(s):  
Photoelectron Spectroscopy ◽  
Raw Materials ◽  
High Surface ◽  
High Surface Area ◽  
Tetragonal Zirconia ◽  
Zirconium Oxychloride ◽  
Dihydrogen Phosphate ◽  
Hydrothermal Conditions ◽  
Hydrothermal Temperature ◽  
X Ray

Using zirconium oxychloride hydrate ( ZrOCl2•8H2O) and ammonia water (NH3•H2O) as raw materials, and ammonium dihydrogen phosphate (NH4H2PO4) as additives, tetragonal zirconia (t-ZrO2) with size range of 8–12 nm were prepared by coprecipitation method under hydrothermal conditions. The influence factors on phase transformation and the particle size such as phosphor loading, hydrothermal temperature and calcination temperature were studied by X-ray diffraction (XRD), Fourier transform Roman spectra (FT-Roman), the Brunauer-Emmett-Teller (BET) method and X-ray photoelectron spectroscopy (XPS) techniques etc. Research results show that a small amount of phosphor has been incorporated into the framework of ZrO2 crystals, producing a certain amount of oxygen vacancies. Phosphor can effectively restrain crystal particles growth and improve the thermal stability of metastable t-ZrO2. The phosphor doped t-ZrO2 had a high surface area (244.2 m2/g). In contrast to the pure ZrO2 particles readily aggregating, the phosphor species deposited on the framework of ZrO2 crystals prevented the agglomeration of the primary particles during calcinations.

XPS STUDIES OF THE STABILITY OF A ZIRCONIUM CARBIDE FILM IN THE PRESENCE OF ZIRCONIUM OXIDE AND HYDROGEN

1995 ◽  
Vol 02 (03) ◽  
pp. 297-303 ◽  
Author(s):  
P.C. WONG ◽  
Y.S. LI ◽  
K.A.R. MITCHELL
Keyword(s):  
Oxide Film ◽  
Photoelectron Spectroscopy ◽  
Zirconium Oxide ◽  
Room Temperature ◽  
Hydrogen Plasma ◽  
Zirconium Carbide ◽  
X Ray ◽  
The Stability ◽  
Zirconium Oxide Film ◽  
Carbide Component

X-ray photoelectron spectroscopy (XPS) has been used to study the interfacial chemistries of a 65-Å film prepared by depositing zirconium in an oxidizing environment onto a methane-pretreated 11-Å thick zirconium oxide film, which initially was deposited onto a gold substrate. The second metal deposition results in an outermost region composed of a mixed zirconium oxide, while below there is metallic zirconium followed by zirconium carbide and carbon on top of the first zirconium oxide film, which is itself in contact with the gold. The carbide component showed no changes on heating to 425°C, on treating with a hydrogen plasma at room temperature, or on heating the resulting film to 425°C. The oxide layers do show characteristic changes, and this also contrasts with earlier observations for a zirconium sulphide film. The zirconium carbide Zr3d 5/2 component has a binding energy of 180.6 eV.

scholarly journals in Situ X-ray Photoelectron Spectroscopic and Electrochemical Studies of the Bromide Anions Dissolved in 1-Ethyl-3-Methyl Imidazolium Tetrafluoroborate

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 304 ◽  
Author(s):  
Jaanus Kruusma ◽  
Arvo Tõnisoo ◽  
Rainer Pärna ◽  
Ergo Nõmmiste ◽  
Enn Lust
Keyword(s):  
Photoelectron Spectroscopy ◽  
Mesoporous Carbon ◽  
Residual Water ◽  
Carbon Electrode ◽  
Xps Spectra ◽  
X Ray ◽  
In Situ Xps ◽  
Vacuum Interface ◽  
Photoelectron Peak

Influence of electrode potential on the electrochemical behavior of a 1-ethyl-3-methylimidazolium tetrafluoroborate (EMImBF4) solution containing 5 wt % 1-ethyl-3-methylimidazolium bromide (EMImBr) has been investigated using electrochemical and synchrotron-initiated high-resolution in situ X-ray photoelectron spectroscopy (XPS) methods. Observation of the Br 3d5/2 in situ XPS signal, collected in a 5 wt % EMImBr solution at an EMImBF4–vacuum interface, enabled the detection of the start of the electrooxidation process of the Br- anion to Br3- anion and thereafter to the Br2 at the micro-mesoporous carbon electrode, polarized continuously at the high fixed positive potentials. A new photoelectron peak, corresponding to B–O bond formation in the B 1s in situ XPS spectra at E ≤ –1.17 V, parallel to the start of the electroreduction of the residual water at the micro-mesoporous carbon electrode, was observed and is discussed. The electroreduction of the residual water caused a reduction in the absolute value of binding energy vs. potential plot slope twice to ca. dBE dE-1 = –0.5 eV V-1 at E ≤ –1.17 V for C 1s, N 1s, B 1s, F 1s, and Br 3d5/2 photoelectrons.

Effect of diffuse layer and pore shapes in mesoporous carbon supercapacitors

2010 ◽  
Vol 25 (8) ◽  
pp. 1469-1475 ◽  
Author(s):  
Jingsong Huang ◽  
Rui Qiao ◽  
Bobby G. Sumpter ◽  
Vincent Meunier
Keyword(s):  
Pore Size ◽  
Mesoporous Carbon ◽  
Diffuse Layer ◽  
Pore Shape ◽  
Mesoporous Carbons ◽  
Cylindrical Pores ◽  
Theoretical Evolution ◽  
Poisson Boltzmann ◽  
Slit Pores ◽  
Carbon Supercapacitors

In the spirit of the theoretical evolution from the Helmholtz model to the Gouy–Chapman–Stern model for electric double-layer capacitors, we explored the effect of a diffuse layer on the capacitance of mesoporous carbon supercapacitors by solving the Poisson–Boltzmann (PB) equation in mesopores of diameters from 2 to 20 nm. To evaluate the effect of pore shape, both slit and cylindrical pores were considered. We found that the diffuse layer does not affect the capacitance significantly. For slit pores, the area-normalized capacitance is nearly independent of pore size, which is not experimentally observed for template carbons. In comparison, for cylindrical pores, PB simulations produce a trend of slightly increasing area-normalized capacitance with pore size, similar to that depicted by the electric double-cylinder capacitor model proposed earlier. These results indicate that it is appropriate to approximate the pore shape of mesoporous carbons as being cylindrical and the electric double-cylinder capacitor model should be used for mesoporous carbons as a replacement of the traditional Helmholtz model.

Activation Process and Mechanism of ZrCoCe Getter Films

2019 ◽  
Vol 944 ◽  
pp. 613-618
Author(s):  
Yao Hua Xu ◽  
Yao Zong Sui ◽  
Xiao Zhang ◽  
Hao Liu ◽  
Peng Yuan ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Zirconium Oxide ◽  
Thermal Activation ◽  
Surface Composition ◽  
Zirconium Carbide ◽  
Activation Process ◽  
Dc Magnetron Sputtering ◽  
Activation Temperature ◽  
X Ray ◽  
Highly Porous

In order to study the activation process and mechanism of ZrCoCe, highly porous ZrCoCe getter films were grown by the DC magnetron sputtering method. The effect of activation temperature on the surface composition of the porous ZrCoCe getter films were studied by X-ray photoelectron spectroscopy (XPS). The results shows that the surface of air-exposed porous ZrCoCe film is covered with H2O, CO2 and hydrocarbons, both Zr and Ce exist in the oxidized state, and zirconium oxide starts to reduce at 300 °C. The activation process also results in a sizable Co segregation at surface. In addition, zirconium carbide can be found in the subsurface region of the film after thermal activation treatment.

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