scholarly journals Spherical Sb Core/Nb2O5-C Double-Shell Structured Composite as an Anode Material for Li Secondary Batteries

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1999
Author(s):  
Hyungeun Seo ◽  
Kyungbae Kim ◽  
Jae-Hun Kim
Keyword(s):  
Volume Change ◽  
Photoelectron Spectroscopy ◽  
Active Material ◽  
High Capacity ◽  
Reversible Capacity ◽  
Cycle Performance ◽  
Core Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
Improved Performance

Antimony (Sb)-based materials are considered to be attractive for use in Li secondary battery anodes because of their high capacity. However, their huge volume change during Li insertion-extraction cycling limits their cycle performance. The Sb-active material can be combined with intercalation-based active materials to address these issues. In this study, spherical Sb core/Nb2O5 shell structured composite materials were synthesized through a simple solvothermal process and a carbon coating was simultaneously added during heat treatment using a naphthalene precursor. The resulting double-shelled materials were characterized with X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, and electron microscopy. The electrochemical test results showed that a reversible capacity of more than 450 mAh g−1 was retained after 100 cycles. This improved performance is ascribed to the double-shelled structure. The large volume change of the nano-sized Sb core material was alleviated by the double-shelled structure, which consisted of crystalline orthorhombic Nb2O5 and amorphous carbon. The shell materials also aided rapid charge transport.

New Iron Oxide Positive Active Material for Lithium Secondary Batteries

1998 ◽  
Vol 548 ◽  
Author(s):  
K. Amine ◽  
H. Yasuda ◽  
M. Yamachi
Keyword(s):  
Iron Oxide ◽  
Electrode Material ◽  
Photoelectron Spectroscopy ◽  
Active Material ◽  
High Capacity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lithium Secondary Batteries ◽  
Divalent State ◽  
V Region

ABSTRACTBeta-iron oxy-hydroxide, which exhibits a (2×2) tunnel-type structure similar to that of (α-MnO2, was found to intercalate reversibly lithium in the tunnels. This material exhibits three voltage plateaus at 2.3, 1.5 and 0.7 V and has an over all discharge capacity of 1100 mAh/g. When cycling in the 2–V region, the material exhibits high capacity of 275 mAh/g and very good cyclic reversibility. X-ray photoelectron spectroscopy (XPS) of the discharged material showed that iron is reduced to the divalent state, and the lithium incorporated in the tunnels is purely ionic. This result explains the good reversibility of this electrode material. When discharged to 0.5 V, however, the structure of the material collapsed, and metallic iron was detected in the X-ray diffraction pattern.

scholarly journals Cr-Doped Li2ZnTi3O8 as a High Performance Anode Material for Lithium-Ion Batteries

2021 ◽  
Vol 8 ◽  
Author(s):  
Xianguang Zeng ◽  
Jing Peng ◽  
Huafeng Zhu ◽  
Yong Gong ◽  
Xi Huang
Keyword(s):  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Electrochemical Impedance ◽  
Performance Testing ◽  
Lithium Ion ◽  
Reversible Capacity ◽  
Cycle Performance ◽  
Phase Method ◽  
Rate Performance ◽  
X Ray

Li2ZnTi2.9Cr0.1O8 and Li2ZnTi3O8 were synthesized by the liquid phase method and then studied comparatively using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), galvanostatic charge–discharge testing, cyclic stability testing, rate performance testing, and electrochemical impedance spectroscopy (EIS). The results showed that Cr-doped Li2ZnTi3O8 exhibited much improved cycle performance and rate performance compared with Li2ZnTi3O8. Li2ZnTi2.9Cr0.1O8 exhibited a discharge ability of 156.7 and 107.5 mA h g−1 at current densities of 2 and 5 A g−1, respectively. In addition, even at a current density of 1 A g−1, a reversible capacity of 162.2 mA h g−1 was maintained after 200 cycles. The improved electrochemical properties of Li2ZnTi2.9Cr0.1O8 are due to its increased electrical conductivity.

scholarly journals Electrochemically Treated TiO2 for Enhanced Performance in Aqueous Al-Ion Batteries

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2090 ◽  
Author(s):  
Alexander Holland ◽  
Rachel McKerracher ◽  
Andrew Cruden ◽  
Richard Wills
Keyword(s):  
Photoelectron Spectroscopy ◽  
Coulombic Efficiency ◽  
Low Cost ◽  
Electrochemical Treatment ◽  
Open Circuit ◽  
High Rate ◽  
Tio2 Electrode ◽  
X Ray Diffraction ◽  
X Ray ◽  
Improved Performance

The potential for low cost, environmentally friendly and high rate energy storage has led to the study of anatase-TiO2 as an electrode material in aqueous Al3+ electrolytes. This paper describes the improved performance from an electrochemically treated composite TiO2 electrode for use in aqueous Al-ion batteries. After application of the cathodic electrochemical treatment in 1 mol/dm3 KOH, Mott–Schottky analysis showed the treated electrode as having an increased electron density and an altered open circuit potential, which remained stable throughout cycling. The cathodic treatment also resulted in a change in colour of TiO2. Treated-TiO2 demonstrated improved capacity, coulombic efficiency and stability when galvanostatically cycled in 1 mol·dm−3AlCl3/1 mol·dm−3 KCl. A treated-TiO2 electrode produced a capacity of 15.3 mA·h·g−1 with 99.95% coulombic efficiency at the high specific current of 10 A/g. Additionally, X-ray diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy were employed to elucidate the origin of this improved performance.

IMPROVED CAPACITIVE BEHAVIOR OF MnO2 THIN FILMS PREPARED BY ELECTRODEPOSITION ON THE PT SUBSTRATE WITH A MnOx BUFFER LAYER

2009 ◽  
Vol 02 (01) ◽  
pp. 13-18 ◽  
Author(s):  
H. XIA ◽  
W. XIAO ◽  
M. O. LAI ◽  
L. LU
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Buffer Layer ◽  
Photoelectron Spectroscopy ◽  
Rate Capability ◽  
Reference Electrode ◽  
Cycle Performance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Supercapacitor Application

Nanostructured MnO 2 thin films were prepared on two types of substrates, Pt / Ti / SiO 2/ Si (PT) and MnO x/ Pt / Ti / SiO 2/ Si ( MnO x/ PT ), by the technique of cyclic-voltammetric electrodeposition. The MnO x buffer layer was deposited on the PT substrate by pulsed laser deposition (PLD). The as-deposited MnO 2 thin films were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and X-ray photoelectron spectroscopy (XPS). The electrochemical properties of the thin film MnO 2 electrodes were investigated using cyclic voltammetry (CV) in 1 M Na 2 SO 4 electrolyte. It was found that the adhesion between the MnO 2 film and the Pt substrate was poor, resulting in cracks and peeling of the MnO 2 film after deposition. However, the adhesion of the MnO 2 film with the MnO x buffer layer was greatly improved, resulting in superior pseudocapacitive performance of the thin film electrodes. A specific capacitance of about 364 F/g of MnO 2 thin films deposited on the MnO x buffer layer can be obtained at a scan rate of 10 mV/s in the voltage window between 0 and 0.9 V versus the Ag / AgCl reference electrode. The MnO 2 thin film deposited on the MnO x/ PT substrate exhibits good rate capability and excellent cycle performance, which makes it promising for supercapacitor application.

Investigation of the Effect of Uv-Assisted Oxidation and Nitridation of Hafnium Metal Films

2003 ◽  
Vol 780 ◽  
Author(s):  
C. Essary ◽  
V. Craciun ◽  
J. M. Howard ◽  
R. K. Singh
Keyword(s):  
Uv Radiation ◽  
Photoelectron Spectroscopy ◽  
Grazing Angle ◽  
X Ray Diffraction ◽  
Metal Thin Films ◽  
X Ray ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force ◽  
Silicon Interface

AbstractHf metal thin films were deposited on Si substrates using a pulsed laser deposition technique in vacuum and in ammonia ambients. The films were then oxidized at 400 °C in 300 Torr of O2. Half the samples were oxidized in the presence of ultraviolet (UV) radiation from a Hg lamp array. X-ray photoelectron spectroscopy, atomic force microscopy, and grazing angle X-ray diffraction were used to compare the crystallinity, roughness, and composition of the films. It has been found that UV radiation causes roughening of the films and also promotes crystallization at lower temperatures.Furthermore, increased silicon oxidation at the interface was noted with the UVirradiated samples and was shown to be in the form of a mixed layer using angle-resolved X-ray photoelectron spectroscopy. Incorporation of nitrogen into the film reduces the oxidation of the silicon interface.

scholarly journals α-Cellulose Fibers of Paper-Waste Origin Surface-Modified with Fe3O4 and Thiolated-Chitosan for Efficacious Immobilization of Laccase

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 581
Author(s):  
Gajanan S. Ghodake ◽  
Surendra K. Shinde ◽  
Ganesh D. Saratale ◽  
Rijuta G. Saratale ◽  
Min Kim ◽  
...  
Keyword(s):  
Enzyme Immobilization ◽  
Photoelectron Spectroscopy ◽  
Cellulose Fibers ◽  
Relative Activity ◽  
Significant Activity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Laccase Immobilization ◽  
Surface Modified

The utilization of waste-paper-biomass for extraction of important α-cellulose biopolymer, and modification of extracted α-cellulose for application in enzyme immobilization can be extremely vital for green circular bio-economy. Thus, in this study, α-cellulose fibers were super-magnetized (Fe3O4), grafted with chitosan (CTNs), and thiol (-SH) modified for laccase immobilization. The developed material was characterized by high-resolution transmission electron microscopy (HR-TEM), HR-TEM energy dispersive X-ray spectroscopy (HR-TEM-EDS), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FT-IR) analyses. Laccase immobilized on α-Cellulose-Fe3O4-CTNs (α-Cellulose-Fe3O4-CTNs-Laccase) gave significant activity recovery (99.16%) and laccase loading potential (169.36 mg/g). The α-Cellulose-Fe3O4-CTNs-Laccase displayed excellent stabilities for temperature, pH, and storage time. The α-Cellulose-Fe3O4-CTNs-Laccase applied in repeated cycles shown remarkable consistency of activity retention for 10 cycles. After the 10th cycle, α-Cellulose-Fe3O4-CTNs possessed 80.65% relative activity. Furthermore, α-Cellulose-Fe3O4-CTNs-Laccase shown excellent degradation of pharmaceutical contaminant sulfamethoxazole (SMX). The SMX degradation by α-Cellulose-Fe3O4-CTNs-Laccase was found optimum at incubation time (20 h), pH (3), temperatures (30 °C), and shaking conditions (200 rpm). Finally, α-Cellulose-Fe3O4-CTNs-Laccase gave repeated degradation of SMX. Thus, this study presents a novel, waste-derived, highly capable, and super-magnetic nanocomposite for enzyme immobilization applications.

scholarly journals Photocatalytic Reduction of CO2 to Methanol Using a Copper-Zirconia Imidazolate Framework

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 346
Author(s):  
Sonam Goyal ◽  
Maizatul Shima Shaharun ◽  
Ganaga Suriya Jayabal ◽  
Chong Fai Kait ◽  
Bawadi Abdullah ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Catalyst Support ◽  
Oxidation Potential ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molar Ratios ◽  
Optimum Parameters ◽  
Reduction Of Co2 ◽  
Enhanced Yield

A set of novel photocatalysts, i.e., copper-zirconia imidazolate (CuZrIm) frameworks, were synthesized using different zirconia molar ratios (i.e., 0.5, 1, and 1.5 mmol). The photoreduction process of CO2 to methanol in a continuous-flow stirred photoreactor at pressure and temperature of 1 atm and 25 °C, respectively, was studied. The physicochemical properties of the synthesized catalysts were studied using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and photoluminescence (PL) spectroscopy. The highest methanol activity of 818.59 µmol/L.g was recorded when the CuZrIm1 catalyst with Cu/Zr/Im/NH4OH molar ratio of 2:1:4:2 (mmol/mmol/mmol/M) was employed. The enhanced yield is attributed to the presence of Cu2+ oxidation state and the uniformly dispersed active metals. The response surface methodology (RSM) was used to optimize the reaction parameters. The predicted results agreed well with the experimental ones with the correlation coefficient (R2) of 0.99. The optimization results showed that the highest methanol activity of 1054 µmol/L.g was recorded when the optimum parameters were employed, i.e., stirring rate (540 rpm), intensity of light (275 W/m2) and photocatalyst loading (1.3 g/L). The redox potential value for the CuZrIm1 shows that the reduction potential is −1.70 V and the oxidation potential is +1.28 V for the photoreduction of CO2 to methanol. The current work has established the potential utilization of the imidazolate framework as catalyst support for the photoreduction of CO2 to methanol.

scholarly journals Study on the Electrical, Structural, Chemical and Optical Properties of PVD Ta(N) Films Deposited with Different N2 Flow Rates

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 937
Author(s):  
Yingying Hu ◽  
Md Rasadujjaman ◽  
Yanrong Wang ◽  
Jing Zhang ◽  
Jiang Yan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Optical Properties ◽  
Photoelectron Spectroscopy ◽  
Crystal Size ◽  
Silicon Substrates ◽  
X Ray Diffraction ◽  
Dc Magnetron Sputtering ◽  
Flow Rates ◽  
X Ray ◽  
N2 Flow Rate

By reactive DC magnetron sputtering from a pure Ta target onto silicon substrates, Ta(N) films were prepared with different N2 flow rates of 0, 12, 17, 25, 38, and 58 sccm. The effects of N2 flow rate on the electrical properties, crystal structure, elemental composition, and optical properties of Ta(N) were studied. These properties were characterized by the four-probe method, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and spectroscopic ellipsometry (SE). Results show that the deposition rate decreases with an increase of N2 flows. Furthermore, as resistivity increases, the crystal size decreases, the crystal structure transitions from β-Ta to TaN(111), and finally becomes the N-rich phase Ta3N5(130, 040). Studying the optical properties, it is found that there are differences in the refractive index (n) and extinction coefficient (k) of Ta(N) with different thicknesses and different N2 flow rates, depending on the crystal size and crystal phase structure.

scholarly journals Optical, XPS and XRD Studies of Semiconducting Copper Sulfide Layers on a Polyamide Film

2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Valentina Krylova ◽  
Mindaugas Andrulevičius
Keyword(s):  
Photoelectron Spectroscopy ◽  
Copper Sulfide ◽  
Diffusion Method ◽  
X Ray Diffraction ◽  
Xps Spectra ◽  
X Ray ◽  
Xrd Studies ◽  
Polyamide Film ◽  
Indirect Band Gap ◽  
Xrd Method

Copper sulfide layers were formed on polyamide PA 6 surface using the sorption-diffusion method. Polymer samples were immersed for 4 and 5 h in 0.15 mol⋅  solutions and acidified with HCl (0.1 mol⋅) at . After washing and drying, the samples were treated with Cu(I) salt solution. The samples were studied by UV/VIS, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) methods. All methods confirmed that on the surface of the polyamide film a layer of copper sulfide was formed. The copper sulfide layers are indirect band-gap semiconductors. The values of are 1.25 and 1.3 eV for 4 h and 5 h sulfured PA 6 respectively. Copper XPS spectra analyses showed Cu(I) bonds only in deeper layers of the formed film, while in sulfur XPS S 2p spectra dominating sulfide bonds were found after cleaning the surface with ions. It has been established by the XRD method that, beside , the layer contains as well. For PA 6 initially sulfured 4 h, grain size forchalcocite, , was  nm and fordjurleite, , it was 54.17 nm. The sheet resistance of the obtained layer varies from 6300 to 102 .

scholarly journals Biodiesel Production on Monometallic Pt, Pd, Ru, and Ag Catalysts Supported on Natural Zeolite

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 48
Author(s):  
Pawel Mierczynski ◽  
Magdalena Mosińska ◽  
Lukasz Szkudlarek ◽  
Karolina Chalupka ◽  
Misa Tatsuzawa ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Natural Zeolite ◽  
Noble Metals ◽  
Methyl Esters ◽  
Physicochemical Characteristics ◽  
Biodiesel Production ◽  
X Ray Diffraction ◽  
X Ray ◽  
Yield Values ◽  
Temperature Programmed

Biodiesel production from rapeseed oil and methanol via transesterification reaction facilitated by various monometallic catalyst supported on natural zeolite (NZ) was investigated. The physicochemical characteristics of the synthesized catalysts were studied by X-ray diffraction (XRD), Brunauer–Emmett–Teller method (BET), temperature-programmed-reduction in hydrogen (H2-TPR), temperature-programmed-desorption of ammonia (NH3-TPD), Scanning Electron Microscope equipped with EDX detector (SEM-EDS), and X-ray photoelectron spectroscopy (XPS) methods. The highest activity and methyl ester yields were obtained for the Pt/NZ catalyst. This catalyst showed the highest triglycerides conversion of 98.9% and fatty acids methyl esters yields of 94.6%. The activity results also confirmed the high activity of the carrier material (NZ) itself in the investigated reaction. Support material exhibited 90.5% of TG conversion and the Fatty Acid Methyl Esters yield (FAME) of 67.2%. Introduction of noble metals improves the TG conversion and FAME yield values. Increasing of the metal loading from 0.5 to 2 wt.% improves the reactivity properties of the investigated catalysts.

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