Preparation, Microwave Absorption and Infrared Emissivity of Ni-doped ZnO/Al Powders by Coprecipitation Method in the GHz Range

In this work, Ni-doped ZnO/Al composites were prepared by a facile chemical co-precipitation method. The morphology and structure of the as-prepared composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS), respectively. It was found that the flake-like Al powders were successfully coated by Ni-doped ZnO nanoparticles with slight aggregation and Ni[Formula: see text] was successfully doped into the crystal lattice of ZnO. Moreover, the effects of ZnO concentration and doped Ni concentration on the infrared emissivity of ZnO/Al composites at the waveband range of 8–14[Formula: see text][Formula: see text]m were studied. The results showed that the ZnO/Al composites exhibited the lowest infrared emissivity of 0.34 with 50[Formula: see text]wt.% ZnO concentration. Meanwhile, the electromagnetic parameters and microwave absorbing properties of Ni-doped ZnO/Al composites in the frequency range of 2–18[Formula: see text]GHz were explored. Significantly, 12[Formula: see text]mol.% Ni-doped ZnO/Al composites presented the lowest infrared emissivity of 0.37 and the maximum reflection loss reached [Formula: see text]32.5[Formula: see text]dB at 13.6[Formula: see text]GHz with a thickness of 4.5[Formula: see text]mm. The excellent microwave absorbing properties could be attributed to the good impedance match, crystal lattice defects and interfacial polarization. It was believed that the Ni-doped ZnO/Al composites could be used as potential infrared-microwave compatible stealth materials.

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

Scientific Reports ◽

10.1038/s41598-020-71934-7 ◽

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.

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

Water ◽

10.3390/w13162189 ◽

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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Study on the Gas Sensitivity of a CeO2 Based Ceramic Sensing Element: Structure and Characteristic

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.280-283.305 ◽

2007 ◽

Vol 280-283 ◽

pp. 305-310

Author(s):

Tao Yan ◽

Xiao Lin Liu ◽

Jian Feng Chen

Keyword(s):

Electron Microscopy ◽

Photoelectron Spectroscopy ◽

Chemical Precipitation ◽

Precipitation Method ◽

Sensing Element ◽

Gas Sensitivity ◽

X Ray ◽

Sensing Properties ◽

Surface Areas ◽

Electron Microscopy Analysis

The sensitivity of CuO dispersed on fluorite-type oxide, namely CeO2 was studied in this work. Mixed oxide sample of nanostructured CuxCe1-xO2-y of various composition were generated by step chemical precipitation method. Distinct copper species were identified as a function of copper content by X-ray photoelectron spectroscopy, X-ray powder diffraction, the special surface areas, transmission electron microscopy, scanning electron microscopy analysis, and sensing properties to CO. It was found that only small amounts of copper are sufficient to promote the sensitivity of CeO2 by several orders of magnitude, which excessive amounts of copper (Cu/(Cu+Ce)>0.12) are detrimental to the sensing properties of nanocompositions. The possible causes for this behavior are also discussed.

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

NANO ◽

10.1142/s1793292017500540 ◽

2017 ◽

Vol 12 (05) ◽

pp. 1750054 ◽

Cited By ~ 4

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%).

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

International Journal of Materials Research (formerly Zeitschrift fuer Metallkunde) ◽

10.1515/ijmr-2020-1111008 ◽

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.

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Preparation of graphene/Fe3O4/Ni electromagnetic microwave absorbing nano-composite materials

International Journal of Modern Physics B ◽

10.1142/s0217979219400551 ◽

2019 ◽

Vol 33 (01n03) ◽

pp. 1940055 ◽

Cited By ~ 4

Author(s):

Yu-Wei Huang ◽

Yu-Jiang Wang ◽

Shi-Cheng Wei ◽

Yi Liang ◽

Wei Huang ◽

...

Keyword(s):

Composite Materials ◽

Photoelectron Spectroscopy ◽

Network Analyzer ◽

Absorption Properties ◽

Microwave Absorption Properties ◽

Nano Composite ◽

X Ray ◽

Microwave Absorbing Properties ◽

One Step ◽

Microwave Absorbing

Graphene/Fe3O4/Ni nano-composite materials were prepared by one-step hydrothermal method from RGO, FeCl3 ⋅ 6H2O and purity Ni. The structure and electromagnetic microwave absorbing properties were investigated systematically by field emission scanning electron microscope (FESEM), X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS) and vector network analyzer (VNA). The reflectance was simulated based on the electromagnetic parameters to evaluate the absorption properties of the sample. The results show that Fe3O4 and Ni are on the surface of graphene evenly, the composites exhibit excellent microwave absorption properties, reflection loss and broad effective absorption bandwidth are −16.38 dB and 3.60 GHz, as the paraffin wax is 40% and the matching thickness is 2.00–3.50 mm.

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AgBr/(Sr0.6Bi0.305)2Bi2O7 Heterostructured Composites: Fabrication, Characterization, and Significantly Enhanced Photocatalytic Activity

Catalysts ◽

10.3390/catal9050394 ◽

2019 ◽

Vol 9 (5) ◽

pp. 394 ◽

Cited By ~ 3

Author(s):

Xinling Wang ◽

Di Zhu ◽

Yan Zhong ◽

Dianhui Wang ◽

Chaohao Hu

Keyword(s):

Electron Microscopy ◽

Photocatalytic Activity ◽

Photoelectron Spectroscopy ◽

Photocatalytic Performance ◽

Diffuse Reflectance Spectroscopy ◽

Precipitation Method ◽

Light Illumination ◽

X Ray ◽

Transmission Electron ◽

Pyrochlore Type

The pyrochlore-type (Sr0.6Bi0.305)2Bi2O7 (SBO) containing Bi3+ and Bi5+ mixed valent states was first investigated as a photocatalyst in our very recent work. To further improve the photocatalytic performance, AgBr/SBO heterostructured composites were synthesized by using a deposition-precipitation method. The characterization of phase structure, morphology, microstructure, elemental composition, and optical properties of the obtained products were performed using X-ray diffractometer (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM)TEM, X-ray photoelectron spectroscopy (XPS), UV-visible diffuse reflectance spectroscopy (UV-vis DRS). The photocatalytic activity of samples was evaluated by degrading methylene blue under visible light illumination. AgBr/SBO composites possess high stability and significantly enhanced photocatalytic performance. The improvement of photocatalytic activity is due to the enhanced light absorption and the separation of photoinduced electrons and holes on the interface of AgBr/SBO heterostructured composites.

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Synthesis and Microwave-Absorbing Properties of Ni-Carbon Sphere Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.399-401.552 ◽

2011 ◽

Vol 399-401 ◽

pp. 552-555 ◽

Cited By ~ 1

Author(s):

Yuan Guang Zhang ◽

Hong Yu Xia ◽

Ying Guo Zhao

Keyword(s):

Electron Microscopy ◽

Solid Phase ◽

Energy Dispersive Spectrometer ◽

Synthetic Approach ◽

Carbon Sphere ◽

X Ray Diffraction ◽

X Ray ◽

Microwave Absorbing Properties ◽

Transmission Electron ◽

Microwave Absorbing

A simple solid-phase synthetic approach has been exploited for the preparation of Ni-carbon sphere composites using Ni(CH3COO)2•4H2O as nickel source, and vitamin C (L-ascorbic acid) as reductant and carbon source at 500oC for 6 h. The products were characterized by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray energy dispersive spectrometer (EDS), raman spectroscopy and microwave-absorbing measurement. The results show that the products are composed of Ni-carbon sphere particles with average diameters of 1.2 µm. Each sphere particle contains embedded Ni particles with average diameters of 83 nm. The reflection loss (RL) values of the products are lower −10 dB at 2–18 GHz, displaying broad range of microwave absorption. Their minimum RL value is about −33 dB at 4.2 GHz, which exhibit good microwave absorbing properties.

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Hydrous Hydrazine Decomposition for Hydrogen Production Using of Ir/CeO2: Effect of Reaction Parameters on the Activity

Nanomaterials ◽

10.3390/nano11051340 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1340

Author(s):

Davide Motta ◽

Ilaria Barlocco ◽

Silvio Bellomi ◽

Alberto Villa ◽

Nikolaos Dimitratos

Keyword(s):

Electron Microscopy ◽

Photoelectron Spectroscopy ◽

Inductively Coupled Plasma ◽

Precipitation Method ◽

Reaction Conditions ◽

X Ray ◽

Inductively Coupled ◽

Transmission Electron ◽

Icp Ms ◽

Hydrazine Decomposition

In the present work, an Ir/CeO2 catalyst was prepared by the deposition–precipitation method and tested in the decomposition of hydrazine hydrate to hydrogen, which is very important in the development of hydrogen storage materials for fuel cells. The catalyst was characterised using different techniques, i.e., X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscopy (SEM) equipped with X-ray detector (EDX) and inductively coupled plasma—mass spectroscopy (ICP-MS). The effect of reaction conditions on the activity and selectivity of the material was evaluated in this study, modifying parameters such as temperature, the mass of the catalyst, stirring speed and concentration of base in order to find the optimal conditions of reaction, which allow performing the test in a kinetically limited regime.

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Electrochemical Capacitive Properties of CuO Nanorods Prepared by a Facile Microwave-Assisted Synthesis Method

Journal of Nano Research ◽

10.4028/www.scientific.net/jnanor.62.21 ◽

2020 ◽

Vol 62 ◽

pp. 21-30

Author(s):

Wei Li ◽

Na Na Feng

Keyword(s):

Electron Microscopy ◽

Photoelectron Spectroscopy ◽

Synthesis Method ◽

Precipitation Method ◽

Microwave Assisted Synthesis ◽

X Ray ◽

Microwave Assisted ◽

Capacitance Performance ◽

Capacitive Properties ◽

Cuo Nanorods

CuO nanorods were fabricated by a facile microwave-assisted synthesis method and applied to pseudo-capacitor. The CuO nanorods were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The capacitive behavior of nanorods was investigated by cyclic voltammetry and galvanostatic charge–discharge measurements. Electrochemical experiments reveal that CuO nanorods demonstrate better capacitance performance than granular CuOs prepared by chemical precipitation method. The CuO nanorods have a high specific capacitance of 317 F/g at a current density of 1 A/g and a fairly good cyclic stability.

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