Effect of Zn2+ and F− Co-Modification on the Structure and Electrochemical Performance of Li4Ti5O12 Anode Material

NANO ◽  
2017 ◽  
Vol 12 (05) ◽  
pp. 1750054 ◽  
Author(s):  
Aijia Wei ◽  
Wen Li ◽  
Lihui Zhang ◽  
Xiaohui Li ◽  
Xue Bai ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Coating Layer ◽  
Rate Capability ◽  
Precipitation Method ◽  
Charge Capacity ◽  
X Ray ◽  
Modification Process ◽  
Co Precipitation ◽  
A Charge

Zn[Formula: see text] and F[Formula: see text] ions are successfully used to modify pure Li4Ti5O[Formula: see text] via a co-precipitation method followed by calcination at 400[Formula: see text]C for 5[Formula: see text]h in an Ar atmosphere in order to further investigate the reaction mechanism of the fluoride modification process. Zn[Formula: see text] and F[Formula: see text] co-modified Li4Ti5O[Formula: see text] samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and electrochemical measurements. After the modification process, no ZnF2 coating layer is formed on the surface of Li4Ti5O[Formula: see text], instead, F[Formula: see text] ions react with Li4Ti5O[Formula: see text] to generate a new phase, composed of a small amount of anatase TiO2, rutile TiO2, LiF, and Zn[Formula: see text] ions are suspected to form a ZnO coating layer on Li4Ti5O[Formula: see text] particles. The electrolyte reduction decomposition is suppressed in Zn[Formula: see text] and F[Formula: see text] co-modified Li4Ti5O[Formula: see text] due to the ZnO coating layer. 1[Formula: see text]wt.% Zn[Formula: see text] and F[Formula: see text] co-modified Li4Ti5O[Formula: see text] exhibits the best rate capability, which leads to a charge capacity of 236.7, 227.8, 222.1, 202.7, 188.9 and 150.7[Formula: see text]mAh g[Formula: see text] at 0.2C, 0.5C, 1C, 3C, 5C and 10C, respectively, between 0[Formula: see text]V and 3[Formula: see text]V. Furthermore, 1[Formula: see text]wt.% Zn[Formula: see text] and F[Formula: see text] co-modified Li4Ti5O[Formula: see text] exhibits 96.0% charge capacity retention at 3C rate after 200 cycles, which is significantly higher than that of pure Li4Ti5O[Formula: see text] (78.4%).

scholarly journals Bio-assisted preparation of efficiently architectured nanostructures of γ-Fe2O3 as a molecular recognition platform for simultaneous detection of biomarkers

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Sasikala Sundar ◽  
V. Ganesh
Keyword(s):  
Electron Microscopy ◽  
Iron Oxide ◽  
Photoelectron Spectroscopy ◽  
Simultaneous Detection ◽  
Differential Pulse ◽  
Precipitation Method ◽  
Limit Values ◽  
X Ray ◽  
Co Precipitation ◽  
The Individual

Abstract Magnetic nanoparticles of iron oxide (γ-Fe2O3) have been prepared using bio-assisted method and their application in the field of biosensors is demonstrated. Particularly in this work, different nanostructures of γ-Fe2O3 namely nanospheres (NS), nanograsses (NG) and nanowires (NW) are prepared using a bio-surfactant namely Furostanol Saponin (FS) present in Fenugreek seeds extract through co-precipitation method by following “green” route. Three distinct morphologies of iron oxide nanostructures possessing the same crystal structure, magnetic properties, and varied size distribution are prepared and characterized. The resultant materials are analyzed using field emission scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy, vibrating sample magnetometer and Fourier transform infrared spectroscopy. Moreover, the effect of reaction time and concentration of FS on the resultant morphologies of γ-Fe2O3 nanostructures are systematically investigated. Among different shapes, NWs and NSs of γ-Fe2O3 are found to exhibit better sensing behaviour for both the individual and simultaneous electrochemical detection of most popular biomarkers namely dopamine (DA) and uric acid (UA). Electrochemical studies reveal that γ-Fe2O3 NWs showed better sensing characteristics than γ-Fe2O3 NSs and NGs in terms of distinguishable voltammetric signals for DA and UA with enhanced oxidation current values. Differential pulse voltammetric studies exhibit linear dependence on DA and UA concentrations in the range of 0.15–75 µM and 5 μM – 0.15 mM respectively. The detection limit values for DA and UA are determined to be 150 nM and 5 µM. In addition γ-Fe2O3 NWs modified electrode showed higher sensitivity, reduced overpotential along with good selectivity towards the determination of DA and UA even in the presence of other common interferents. Thus the proposed biosensor electrode is very easy to fabricate, eco-friendly, cheaper and possesses higher surface area suggesting the unique structural patterns of γ-Fe2O3 nanostructures to be a promising candidate for electrochemical bio-sensing and biomedical applications.

Study on photocatalytic activity based on different pH values of AgBr/Ag2CO3 heterojunction

2020 ◽  
Vol 111 (10) ◽  
pp. 842-848
Author(s):  
Fengfeng Li ◽  
Mingxi Zhang ◽  
Jin Wang ◽  
Yongfeng Cai ◽  
Dushao Zhao ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Rhodamine B ◽  
Photoelectron Spectroscopy ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Photocatalytic Activities ◽  
Co Precipitation ◽  
Degradation Degree

Abstract In this work, we fabricate a highly efficient photocatalytic AgBr/Ag2CO3 heterojunction through the co-precipitation method. The obtained samples were characterized by means of X-ray diffraction, scanning electron microscopy, transmission electron microscopy, ultraviolet-visible diffuse reflectance spectra and X-ray photoelectron spectroscopy. The photocatalytic activities of obtained samples can be assessed by visible light (λ ≥ 400 nm) degradation of rhodamine B solution. X-ray diffraction revealed that the crystallinity of the AgBr/Ag2CO3heterojunction was significantly higher than pure AgBr and Ag2CO3. Moreover, the AgBr/ Ag2CO3 heterojunction prepared at pH = 6 has the best photocatalytic performance, it can raise the degradation degree of rhodamine B over 95% at 20 min. Finally, a possible photocatalytic mechanism is discussed.

scholarly journals Preparation and characterization of magnetic graphene oxide nanocomposite (GO-Fe3O4) for removal of strontium and cesium from aqueous solutions

2021 ◽  
Vol 4 (1) ◽  
pp. 26
Author(s):  
Sule Aytas ◽  
Sabriye Yusan ◽  
Senol Sert ◽  
Cem Gok
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Aqueous Solutions ◽  
Photoelectron Spectroscopy ◽  
Precipitation Method ◽  
Magnetic Graphene Oxide ◽  
X Ray ◽  
Magnetic Graphene ◽  
Transmission Electron ◽  
Co Precipitation

Magnetic graphene oxide nanocomposites (M-GO) were successfully synthesized by partial reduction co-precipitation method and used for removal of Sr(II) and Cs(I) ions from aqueous solutions. The structures and properties of the M-GO was investigated by X-ray diffraction, Fourier transformed infrared spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, scanning electron microscopy, vibrating sample magnetometer (VSM) and N2-BET measurements. It is found that M-GO has 2.103 mg/g and 142.070 mg/g adsorption capacities for Sr(II) and Cs(I) ions, respectively. The adsorption isotherm matches well with the Freundlich for Sr(II) and Dubinin–Radushkevich model for Cs(I) and kinetic analysis suggests that the adsorption process is pseudo-second-ordered.

scholarly journals Preparation and characterization of magnetic graphene oxide nanocomposite (GO-Fe3O4) for removal of strontium and cesium from aqueous solutions

2018 ◽  
Vol 7 (1) ◽  
Author(s):  
Sabriye Yusan
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Aqueous Solutions ◽  
Photoelectron Spectroscopy ◽  
Precipitation Method ◽  
Magnetic Graphene Oxide ◽  
X Ray ◽  
Magnetic Graphene ◽  
Transmission Electron ◽  
Co Precipitation

<p>Magnetic graphene oxide nanocomposites (M-GO) were successfully synthesized by partial reduction co-precipitation method and used for removal of Sr(II) and Cs(I) ions from aqueous solutions. The structures and properties of the M-GO was investigated by X-ray diffraction, Fourier transformed infrared spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, scanning electron microscopy, vibrating sample magnetometer (VSM) and N<sub>2</sub>-BET measurements. It is found that M-GO has 2.103 mg/g and 142.070 mg/g adsorption capacities for Sr(II) and Cs(I) ions, respectively. The adsorption isotherm matches well with the Freundlich for Sr(II) and Dubinin–Radushkevich model for Cs(I) and kinetic analysis suggests that the adsorption process is pseudo-second-ordered.</p>

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

Catalysts ◽  
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.

Hydroformylation of Dicyclopentadiene over Rh Catalysts Supported on Fe2O3, Co3O4 and Fe2O3–Co3O4 Mixed Oxide

2017 ◽  
Vol 42 (1) ◽  
pp. 8-13 ◽  
Author(s):  
Yubo Ma ◽  
Zhixian Gao ◽  
Wumanjiang Eli
Keyword(s):  
Mixed Oxide ◽  
Photoelectron Spectroscopy ◽  
Supported Catalyst ◽  
Precipitation Method ◽  
X Ray ◽  
Analysis Techniques ◽  
Rh Catalyst ◽  
Temperature Programmed ◽  
Co Precipitation ◽  
Effect Of The Support

Rh catalysts supported on Fe2O3, Co3O4 and Fe2O3–Co3O4 mixed oxide were prepared by the co-precipitation method. The effect of the support on the performance of the Rh catalysts for the hydroformylation of dicyclopentadiene was investigated using X-ray photoelectron spectroscopy, H2-temperature-programmed reduction, H2-temperature-programmed desorption and Brunauer–Emmett–Teller analysis techniques. The results indicated that the Fe2O3–Co3O4 supported catalyst had a higher dispersion of Rh and thus more Rh+ sites. As a result, the Fe2O3–Co3O4 supported Rh catalyst exhibited higher activity compared with counterparts supported on Fe2O3 and Co3O4.

scholarly journals Effect of Y Modified Ceria Support in Mono and Bimetallic Pd–Au Catalysts for Complete Benzene Oxidation

Catalysts ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 283 ◽  
Author(s):  
Lyuba Ilieva ◽  
Anna Venezia ◽  
Petya Petrova ◽  
Giuseppe Pantaleo ◽  
Leonarda Liotta ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
Benzene Oxidation ◽  
Total Oxidation ◽  
Pd Catalysts ◽  
X Ray ◽  
Close Relationship ◽  
Ceria Support ◽  
Co Precipitation

Mono metallic and bimetallic Pd (1 wt. %)–Au (3 wt. %) catalysts were prepared using two ceria supports doped with 1 wt. % Y2O3. Yttrium was added by impregnation or co-precipitation. The catalyst synthesis was carried out by deposition–precipitation method, with sequential deposition–precipitation of palladium over previously loaded gold in the case of the bimetallic samples. The obtained materials, characterized by X-ray powder diffraction (XRD), High resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and temperature programmed reduction (TPR) techniques, were tested in the complete benzene oxidation (CBO). The results of the characterization analyses and the catalytic performance pointed to a close relationship between structural, redox, and catalytic properties of mono and bimetallic catalysts. Among the monometallic systems, Pd catalysts were more active as compared to the corresponding Au catalysts. The bimetallic systems exhibited the best combustion activity. In particular, over Pd–Au supported on Y-impregnated ceria, 100% of benzene conversion towards total oxidation at the temperature of 150 °C was obtained. Comparison of surface sensitive XPS results of fresh and spent catalysts ascertained the redox character of the reaction.

scholarly journals Synthesis of DME by CO2 hydrogenation over La2O3-modified CuO-ZnO-ZrO2/HZSM-5 catalysts

2017 ◽  
Vol 23 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Yajing Zhang ◽  
Yu Zhang ◽  
Fu Ding ◽  
Kangjun Wang ◽  
Wang Xiaolei ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Direct Synthesis ◽  
Catalytic Performance ◽  
Co2 Hydrogenation ◽  
Precipitation Method ◽  
X Ray ◽  
Temperature Programmed ◽  
And Performance ◽  
Co Precipitation ◽  
Adsorption Desorption

A series of La2O3-modified CuO-ZnO-ZrO2/HZSM-5 catalysts were prepared by an oxalate co-precipitation method. The catalysts were fully characterized by X-ray diffraction (XRD), N2 adsorption-desorption, hydrogen temperature pro-grammed reduction (H2-TPR), ammonia temperature programmed desorption (NH3-TPD), and X-ray photoelectron spectroscopy (XPS) techniques. The effect of the La2O3 content on the structure and performance of the catalysts was thoroughly investigated. The catalysts were evaluated for the direct synthesis of dimethyl ether (DME) from CO2 hydrogenation. The results displayed that La2O3 addition enhanced catalytic performance, and the maximal CO2 conversion (34.3%) and DME selectivity (57.3%) were obtained over the catalyst with 1% La2O3, which due to the smaller size of Cu species and a larger ratio of Cu+/Cu.

scholarly journals Electrochemical Performance of Lanthanum Cerium Ferrite Nanoparticles for Supercapacitor Applications

2021 ◽  
Author(s):  
Waseem Raza ◽  
Ghulam Nabi ◽  
Asim Shahzad ◽  
Nafisa Malik ◽  
Nadeem Raza
Keyword(s):  
Electron Microscopy ◽  
Electrode System ◽  
Ferrite Nanoparticles ◽  
Precipitation Method ◽  
Super Capacitor ◽  
X Ray ◽  
Transmission Electron ◽  
Co Precipitation ◽  
First Time ◽  
Supercapacitor Applications

Abstract Lanthanum cerium ferrite nanoparticles has been synthesized for the first time via hydrothermal and co-precipitation method. The structural and morphological study of the nanoparticles have been examined by using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive x-ray spectroscopy (EDX). The electrochemical study of J1 and J2 electrodes have been examined using three electrode system in 6 M KOH electrolyte using cyclic voltammetry (CV), galvanostatic charging-discharging (GCD) and electrochemical impendence spectroscopy (EIS). The highest specific capacitance of 1195 F/g has been obtained at a scan rate of 10 mV/s from hydrothermal synthesis nanomaterial electrode (J2) and long cycling life 92.3% retention after 2000th cycles. Furthermore, the energy density and power density of the J2 electrode at a current density of 5 A/g was 59 Wh/kg and 9234 W/kg respectively. Hence, the fabricated J2 electrode is a favorable candidate for super-capacitor applications.

scholarly journals Synthesis and Characterization of Sr-Doped ZnSe Nanoparticles for Catalytic and Biological Activities

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2189
Author(s):  
V. Beena ◽  
S. L. Rayar ◽  
S. Ajitha ◽  
Awais Ahmad ◽  
Munirah D. Albaqami ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Antibacterial Activity ◽  
Methyl Orange ◽  
Photoelectron Spectroscopy ◽  
Biological Activities ◽  
Water Remediation ◽  
Precipitation Method ◽  
Znse Nanoparticles ◽  
X Ray ◽  
Degradation Of Methyl Orange

The development of cost-effective and ecofriendly approaches toward water purification and antibacterial activity is a hot research topic in this era. Purposely, strontium-doped zinc selenide (Sr-doped ZnSe) nanoparticles, with different molar ratios of Sr2+ cations (0.01, 0.05, and 0.1), were prepared via the co-precipitation method, in which sodium borohydride (NaBH4) and 2-mercaptoethanol were employed as reducing and stabilizing agents, respectively. The ZnSe cubic structure expanded by Sr2+ cations was indicated by X-ray diffraction (XRD) analysis. The absorption of the chemical compounds on the surface was observed via Fourier transform infrared (FT-IR) spectroscopy. The optical orientation was measured by ultraviolet–visible diffused reflectance spectroscopy (UV-DRS) analysis. The surface area, morphology, and elemental purity were analyzed using field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), and energy-dispersive spectroscopy (EDS) analyses. The oxidation state and valency of the synthesized nanoparticles were analyzed using X-ray photoelectron spectroscopy (XPS). Sr-doped ZnSe nanoparticles were investigated for photocatalytic degradation of methyl orange (MO), and their antibacterial potential was investigated against different bacterial strains. The antibacterial activity examined against Staphylococcus aureus and Escherichia coli implied the excellent biological activity of the nanoparticles. Moreover, the Sr-doped ZnSe nanoparticles were evaluated by the successful degradation of methyl orange under visible light irradiation. Therefore, Sr-doped ZnSe nanoparticles have tremendous potential in biological and water remediation fields.

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