scholarly journals Enhanced Electrochemical Performances of Cobalt-Doped Li2MoO3 Cathode Materials

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 843 ◽  
Author(s):  
Zhiyong Yu ◽  
Jishen Hao ◽  
Wenji Li ◽  
Hanxing Liu
Keyword(s):  
Cathode Materials ◽  
Photoelectron Spectroscopy ◽  
Solid Phase ◽  
Phase Method ◽  
Electrochemical Performances ◽  
X Ray ◽  
Electrochemical Tests ◽  
Co Doping ◽  
Solid Phase Method ◽  
Better Than

Co-doped Li2MoO3 was successfully synthesized via a solid phase method. The impacts of Co-doping on Li2MoO3 have been analyzed by X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD), scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR) measurements. The results show that an appropriate amount of Co ions can be introduced into the Li2MoO3 lattices, and they can reduce the particle sizes of the cathode materials. Electrochemical tests reveal that Co-doping can significantly improve the electrochemical performances of the Li2MoO3 materials. Li2Mo0.90Co0.10O3 presents a first-discharge capacity of 220 mAh·g−1, with a capacity retention of 63.6% after 50 cycles at 5 mA·g−1, which is much better than the pristine samples (181 mAh·g−1, 47.5%). The enhanced electrochemical performances could be due to the enhancement of the structural stability, and the reduction in impedance, due to the Co-doping.

scholarly journals Structural properties of TiO2-SnO2 thin films prepared by new pyrolysis solid-phase method

2021 ◽  
Vol 2086 (1) ◽  
pp. 012042
Author(s):  
M G Volkova ◽  
V Yu Storozhenko ◽  
V V Petrov ◽  
E M Bayan
Keyword(s):  
Solid Phase ◽  
Sem Analysis ◽  
Phase Method ◽  
Materials Properties ◽  
X Ray ◽  
Synthesis Parameters ◽  
Solid Phase Method ◽  
Sno2 Thin Films ◽  
Low Temperature Pyrolysis ◽  
Synthesized Materials

Abstract Nanoscale TiO2-SnO2 films with the Ti:Sn ratio 1:99, 3:97 and 5:95 mol%, respectively, were obtained by solid-phase low-temperature pyrolysis method. The synthesized materials were studied by X-ray phase analysis and scanning electron microscopy (SEM) analysis. Regardless of the modified agents’ concentration, the structure of cassiterite was observed for all synthesized materials. When studying the effect of synthesis parameters on the materials properties, it was shown that both an increase in the Ti4+ concentration and in the calcination temperature leads to an increase in the particle size.

Solubility of Mn in ZnO Crystallites Synthesized Using Solid State Techniques

2020 ◽  
Vol 3 (1) ◽  
pp. 28-39
Author(s):  
Esau Nii Abekah Akwetey Armah ◽  
Martin Egblewogbe ◽  
Hubert Azoda Koffi ◽  
Alfred Ato Yankson ◽  
Francis Kofi Ampong ◽  
...  
Keyword(s):  
Solid Phase ◽  
Solubility Limit ◽  
Phase Method ◽  
Regular Pattern ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
X Ray ◽  
Powder Samples ◽  
Solid Phase Method ◽  
Mn Concentration

Powder samples of Zn1-xMnxO nanocrystal were synthesized at a temperature of 200 °C using solid phase method. Dopant concentrations of 0.005 ≤ x ≤ 0.5 were studied. Powder x-ray diffraction (PXRD) patterns of the samples were analyzed with a view of determining the onset of secondary phases, hence the solubility limit of the dopant. The solubility limit for Mn in ZnO samples synthesized at 200 °C is realized at x < 0.3. With a regular pattern in increment of the Mn concentration, there were variations observed in the trend of the relative intensity, 2θ position and d-spacing indicating uneven addition of Mn (thus Mn2+, Mn3+ or Mn4+).

scholarly journals Luminescence Performance of Yellow Phosphor SrxBa1−xTiO3: Eu3+, Gd3+for Blue Chip

2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Limin Dong ◽  
Jian Li ◽  
Qin Li ◽  
Lianwei Shan ◽  
Zhidong Han
Keyword(s):  
Light Emission ◽  
Solid Phase ◽  
Phase Method ◽  
Photoluminescence Excitation ◽  
X Ray Diffraction ◽  
Yellow Light ◽  
X Ray ◽  
Potential Applications ◽  
Solid Phase Method ◽  
Luminescence Performance

The SrxBa1−xTiO3: Eu3+, Gd3+phosphors are synthesized by high temperature solid-phase method. Multiple techniques including X-ray diffraction (XRD), and scanning electron microscopy (SEM) are used to examine the surface morphology and structural properties of SrxBa1−xTiO3: Eu3+, Gd3+phosphors. The optical properties are presented and discussed in terms of photoluminescence (PL) and photoluminescence excitation (PLE) spectra. The as-obtained SrxBa1−xTiO3: Eu3+, Gd3+phosphors show higher PL emission intensity (at 591, 611 nm). The peaks at 591 and 611 nm are attributed to Eu3+  5D0-7F1,5D0-7F2. Gd3+has a strong sensitization on Eu3+. A certain amount of Sr2+and Ba2+is contributed to the intensity of light emission. After being irradiated with blue light, the phosphor samples emit yellow light. This suggests its potential applications in many fields.

Effects of Cr Doping on the Structural and Electrochemical Properties of V6O13

2010 ◽  
Vol 34-35 ◽  
pp. 1780-1783 ◽  
Author(s):  
Yuan Chun Liu ◽  
Zheng Guang Zou ◽  
Fei Long
Keyword(s):  
Electrochemical Properties ◽  
Cathode Materials ◽  
Solid Phase ◽  
Lithium Ion ◽  
Chain Structure ◽  
Raw Material ◽  
Phase Method ◽  
Discharge Process ◽  
Solid Phase Method ◽  
Cr Doping

It has been demonstrated that V6O13 is a very attractive cathode materials for rechargeable lithium-ion batteries. Cr3+ was doped to improve its electrochemical property. CrxV6O13(x =0.01~0.05) cathode materials were prepared using NH4VO3 and Cr2O3 as raw material by solid phase method in argon atmosphere. The best electrochemical properties of CrxV6O13 were obtained under the optimum conditions as follows: the argon flow rate is 85mL/min, the heating rate is 5°C /min, the holding time 1h at 180°C, 1h at 300°C and 30 min at 450°C. The structural and electrochemical properties were examined by means of X-ray diffraction, SEM and charge–discharge tests. The results demonstrated that the powders maintain double cavity chain structure regardless of the chromium doping. When the Cr doping of x = 0.03, capacity is highest. Maximum initial discharge capacity is 334mA•h/g, 80% of theoretical capacity. During discharge process there is 6.5 Li+ embedded in the Molecules of doping. After discharge cathode became Li6.5Cr0.03V6O13.

scholarly journals High Active PdSn Binary Alloyed Catalysts Supported on B and N Codoped Graphene for Formic Acid Electro-Oxidation

Catalysts ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 751
Author(s):  
Dan Chen ◽  
Shien Pei ◽  
Zhishun He ◽  
Haibo Shao ◽  
Jianming Wang ◽  
...  
Keyword(s):  
Formic Acid ◽  
Photoelectron Spectroscopy ◽  
Metallic Nanoparticles ◽  
Moderate Amount ◽  
X Ray ◽  
Sn Doping ◽  
Electrochemical Tests ◽  
Molar Ratios ◽  
Co Doping ◽  
Electro Oxidation

A series of PdSn binary catalysts with varied molar ratios of Pd to Sn are synthesized on B and N dual-doped graphene supporting materials. The catalysts are characterized by X-ray diffraction (XRD) and Transmission electron microscopy (TEM). Formic acid electro-oxidation reaction is performed on these catalysts, and the results reveal that the optimal proportion of Pd:Sn is 3:1. X-ray photoelectron spectroscopy (XPS) measurements show that when compared with 3Pd1Sn/graphene, B and N co-doping into the graphene sheet can tune the electronic structure of graphene, favoring the formation of small-sized metallic nanoparticles with good dispersion. On the other hand, when compared with the monometallic counterparts, the incorporation of Sn can generate oxygenated species that help to remove the intermediates, exposing more active Pd sites. Moreover, the electrochemical tests illustrate that 3Pd1Sn/BN-G catalyst with a moderate amount of Sn exhibits the best catalytic activity and stability on formic acid electro-oxidation, owing to the synergistic effect of the Sn doping and the B, N co-doping graphene substrate.

scholarly journals Solid-phase synthesis of ytterbium zirconate using mechanical activation

2021 ◽  
Vol 12 (2-2021) ◽  
pp. 154-158
Author(s):  
O. A Kuzmenkov ◽  
◽  
A. M. Kalinkin ◽  
Keyword(s):  
Mechanical Activation ◽  
Solid Phase ◽  
Planetary Mill ◽  
Phase Method ◽  
Stoichiometric Mixture ◽  
Phase Synthesis ◽  
X Ray ◽  
Zirconium Oxides ◽  
Solid Phase Method ◽  
Complex Thermal Analysis

Nanocrystalline ytterbium zirconate Yb4Zr3O12 was prepared by the solid-phase method using mechanical activation of stoichiometric mixture of zirconium and ytterbium oxides. Mechanical activation was carried out in an AGO-2 centrifugal-planetary mill at a centrifugal factor of 40 g for 10 min. The processes occurring during the calcination of the mechanically activated mixture of ytterbium and zirconium oxides in the range from 600 to 1300 °C were investigated using X-ray phase analysis, IR spectroscopy, and complex thermal analysis.

scholarly journals Magnetic Behavior and Nexafs-spectroscopy of Bi₂BaNb₂₋₂ₓСo₂ₓO₉₋δ

2019 ◽  
pp. 687-693 ◽  
Author(s):  
Lubov V. Rychkova ◽  
Sergey V. Nekipelov ◽  
Boris A. Makeev ◽  
Vladimir A. Belyy ◽  
Dmitriy S. Beznosikov ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Solid Solutions ◽  
Electron State ◽  
Solid Phase ◽  
Exchange Interactions ◽  
Magnetic Behavior ◽  
Phase Method ◽  
X Ray ◽  
Nexafs Spectroscopy ◽  
Solid Phase Method

The samples of solid solutions of Bi₂BaNb₂₋₂ₓСo₂ₓO₉₋δ composition at x 0:04 were synthesized by the solid-phase method. The electron state and the nature of the exchange interactions of cobalt atoms in the samples were studied by the measurements of magnetic susceptibility and NEXAFS-spectroscopy. The NEXAFS spectra of the solid solutions and the cobalt oxides CoO, Co3O4 were recorded. According to the data of X-ray spectroscopy and magnetic susceptibility, the charge states of cobalt atoms in the solid solutions were identified as Co(II) and Co(III) in the forms of monomers and exchange-bound aggregates with the antiferromagnetic type of exchange.

S-C3N4 Quantum Dot Decorated ZnO Nanorods to Improve Their Photoelectrochemical Performance

NANO ◽  
2017 ◽  
Vol 12 (05) ◽  
pp. 1750064 ◽  
Author(s):  
Haizhou He ◽  
Jie Li ◽  
Yang Liu ◽  
Qiong Liu ◽  
Faqi Zhan ◽  
...  
Keyword(s):  
Light Absorption ◽  
Photoelectron Spectroscopy ◽  
Seed Layer ◽  
Electrochemical Impedance ◽  
Solid Phase ◽  
Zno Nanorods ◽  
Phase Method ◽  
Photoelectrochemical Performance ◽  
Electrochemical Impedance Spectra ◽  
X Ray

S-doped C3N4 quantum dots (SCNQDs) were synthesized successfully by a low-temperature solid-phase method. The as-synthesised SCNQDs were decorated on ZnO nanorods by a dipping method. The ZnO nanorod films were prepared through a two-stage method, including pulse electrodeposition for depositing ZnO seed layer on fluorine doping SnO2 glass (FTO) and chemical bath for growing ZnO nanorods on the ZnO seed layer. The prepared samples were characterized via scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-vis absorption spectroscopy, X-ray photoelectron spectroscopy (XPS). The photoelectrochemical performances of the prepared samples were estimated using linear sweep voltammograms, electrochemical impedance spectra (EIS), Mott–Schottky, transient photocurrent and incident photon-to-current conversion efficiency (IPCE). The results show that the light absorption edge of the prepared SCNQDs increases from 326[Formula: see text]nm (CNQDs) to 349[Formula: see text]nm after S doping. The CNQD decorated ZnO photoanode film exhibits 1.34 times as high photocurrent as bare ZnO photoanode film. Importantly, the photocurrent increased to 1.79 times than bare ZnO photoanode film by S doping at 1.0[Formula: see text]V (versus Ag/AgCl), which is attributed to a wider light absorption of SCNQDs and a better efficiency of electron transfer in the interface between SCNQDs and ZnO.

scholarly journals Facile Synthesis of Mn0.68Bi0.32OCl Mix-Crystals And Its Supercapacitive Behavior

2021 ◽  
Author(s):  
Y.Z. Song ◽  
B.X. Qi ◽  
M.T. Li ◽  
J.M. Xie
Keyword(s):  
Surface Area ◽  
Solid Phase ◽  
Life Time ◽  
Molar Ratio ◽  
Phase Method ◽  
X Ray Diffraction ◽  
Facile Synthesis ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Solid Phase Method

Abstract Mn0.68Bi0.32OCl mix-crystals for supercapacitor were successfully synthesized via a facile solid-phase method using Bi(NO3)3 and MnCl2 with molar ratio of 1:1 as precursors. The Mn0.68Bi0.32OCl mix-crystals were characterized by scanning electron microscopy, X-ray diffraction, Brunauer-Emmett-Teller surface area measurements and thermogravimetry and differential scanning calorimetry, respectively. Cyclic voltammetry and galvanostatic charge/discharge technique were performed for the Mn0.68Bi0.32OCl mix-crystals in 1 M Na2SO4 aqueous solutions; the specific capacitance of Mn0.68Bi0.32OCl was about 203 F.g-1 at the current density of 3 A. g-1 with a long life time, owing to the high power density of Mn0.68Bi0.32OCl mix-crystals and the higher surface area, good conductivity, and high stability of the Mn0.68Bi0.32OCl mix-crystals.

scholarly journals Preparation of LiFePO4/C Cathode Materials via a Green Synthesis Route for Lithium-Ion Battery Applications

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2251 ◽  
Author(s):  
Rongyue Liu ◽  
Jianjun Chen ◽  
Zhiwen Li ◽  
Qing Ding ◽  
Xiaoshuai An ◽  
...  
Keyword(s):  
Cathode Materials ◽  
Photoelectron Spectroscopy ◽  
Raw Materials ◽  
Lithium Ion ◽  
Lithium Carbonate ◽  
Electrochemical Performances ◽  
Scanning Calorimetry ◽  
Xps Spectra ◽  
X Ray ◽  
Exhaust Purification

In this work, LiFePO4/C composite were synthesized via a green route by using Iron (III) oxide (Fe2O3) nanoparticles, Lithium carbonate (Li2CO3), glucose powder and phosphoric acid (H3PO4) solution as raw materials. The reaction principles for the synthesis of LiFePO4/C composite were analyzed, suggesting that almost no wastewater and air polluted gases are discharged into the environment. The morphological, structural and compositional properties of the LiFePO4/C composite were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), Raman and X-ray photoelectron spectroscopy (XPS) spectra coupled with thermogravimetry/Differential scanning calorimetry (TG/DSC) thermal analysis in detail. Lithium-ion batteries using such LiFePO4/C composite as cathode materials, where the loading level is 2.2 mg/cm2, exhibited excellent electrochemical performances, with a discharge capability of 161 mA h/g at 0.1 C, 119 mA h/g at 10 C and 93 mA h/g at 20 C, and a cycling stability with 98.0% capacity retention at 1 C after 100 cycles and 95.1% at 5 C after 200 cycles. These results provide a valuable approach to reduce the manufacturing costs of LiFePO4/C cathode materials due to the reduced process for the polluted exhaust purification and wastewater treatment.

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