Properties of nanosized ΖnO: Ho films deposited using explosive evaporation

The properties of nanosized ZnO:Ho thin films deposited by explosive evaporation method have been studied. This work is aimed at studying the effect of high deposition rate on the oxide characteristics interesting from the viewpoint of photocatalysis, namely: morphology and structure, electrical and optical properties, lifetime of charge carriers. Explosive deposition of films defines the novelty of this work as compared to majority of previous studies devoted to nanosized ZnO:Ho photocatalysts, which used equilibrium methods for their synthesis. Methods of scanning electron microscopy, XRD analysis, photoluminescence, and Raman scattering have shown that in ZnO:Ho films deposited using explosive evaporation, with increasing holmium content, amorphization of their structure and morphology are observed. It is related with random incorporation of holmium atoms into the crystalline lattice of ZnO as well as with the fact that the ionic radius of Ho3+ exceeds that of Zn2+. It is accompanied by a shift of the edge of ZnO absorption toward the long-wave (blue) spectral range, the decrease of the bandgap as well as an increase in the resistivity and lifetime of charge carriers. All these changes are favourable for the photocatalytic process involving nanostructures based on ZnO:Ho

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NUMERICAL COMPARISON OF WAVE SYNTHESIS METHODS

Coastal Engineering Proceedings ◽

10.9753/icce.v21.6 ◽

1988 ◽

Vol 1 (21) ◽

pp. 6

Author(s):

M.D. Miles ◽

E.R. Funke

Keyword(s):

Statistical Analysis ◽

Time Domain ◽

Synthesis Methods ◽

Numerical Comparison ◽

Comparison Study ◽

Order Group ◽

Wave Parameters ◽

Long Wave ◽

Standard Wave ◽

Wave Synthesis

A numerical comparison study is carried out on a variety of methods for synthesizing pseudo-random Gaussian wave records for laboratory wave generation. Three nonharmonic superposition methods and three time domain filtering procedures are compared to a harmonic FFT technique. The synthesis methods are evaluated on the basis of a statistical analysis of 16 standard wave parameters obtained from a set of 200 wave records. Second order group-bounded long wave components are also investigated.

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Cationic Substitutions in Hydroxyapatite: Current Status of the Derived Biofunctional Effects and Their In Vitro Interrogation Methods

Materials ◽

10.3390/ma11112081 ◽

2018 ◽

Vol 11 (11) ◽

pp. 2081 ◽

Cited By ~ 55

Author(s):

Teddy Tite ◽

Adrian-Claudiu Popa ◽

Liliana Balescu ◽

Iuliana Bogdan ◽

Iuliana Pasuk ◽

...

Keyword(s):

High Performance ◽

Life Time ◽

Crystalline Lattice ◽

Current Status ◽

Synthesis Methods ◽

Biological Interactions ◽

Application Range ◽

Biological Performance

High-performance bioceramics are required for preventing failure and prolonging the life-time of bone grafting scaffolds and osseous implants. The proper identification and development of materials with extended functionalities addressing socio-economic needs and health problems constitute important and critical steps at the heart of clinical research. Recent findings in the realm of ion-substituted hydroxyapatite (HA) could pave the road towards significant developments in biomedicine, with an emphasis on a new generation of orthopaedic and dentistry applications, since such bioceramics are able to mimic the structural, compositional and mechanical properties of the bone mineral phase. In fact, the fascinating ability of the HA crystalline lattice to allow for the substitution of calcium ions with a plethora of cationic species has been widely explored in the recent period, with consequent modifications of its physical and chemical features, as well as its functional mechanical and in vitro and in vivo biological performance. A comprehensive inventory of the progresses achieved so far is both opportune and of paramount importance, in order to not only gather and summarize information, but to also allow fellow researchers to compare with ease and filter the best solutions for the cation substitution of HA-based materials and enable the development of multi-functional biomedical designs. The review surveys preparation and synthesis methods, pinpoints all the explored cation dopants, and discloses the full application range of substituted HA. Special attention is dedicated to the antimicrobial efficiency spectrum and cytotoxic trade-off concentration values for various cell lines, highlighting new prophylactic routes for the prevention of implant failure. Importantly, the current in vitro biological tests (widely employed to unveil the biological performance of HA-based materials), and their ability to mimic the in vivo biological interactions, are also critically assessed. Future perspectives are discussed, and a series of recommendations are underlined.

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Photonic Crystals for Plasmonic Photocatalysis

Catalysts ◽

10.3390/catal10080827 ◽

2020 ◽

Vol 10 (8) ◽

pp. 827 ◽

Cited By ~ 3

Author(s):

Tharishinny Raja-Mogan ◽

Bunsho Ohtani ◽

Ewa Kowalska

Keyword(s):

Photocatalytic Activity ◽

Photonic Crystals ◽

Localized Surface Plasmon Resonance ◽

Wide Bandgap ◽

Charge Carriers ◽

Localized Surface Plasmon ◽

Synthesis Methods ◽

Inverse Opal ◽

Red Edge ◽

Bandgap Semiconductors

Noble metal (NM)-modified wide-bandgap semiconductors with activity under visible light (Vis) irradiation, due to localized surface plasmon resonance (LSPR), known as plasmonic photocatalysts, have been intensively studied over the last few years. Despite the novelty of the topic, a large number of reports have already been published, discussing the optimal properties, synthesis methods and mechanism clarification. It has been proposed that both efficient light harvesting and charge carriers’ migration are detrimental for high and stable activity under Vis irradiation. Accordingly, photonic crystals (PCs) with photonic bandgap (PBG) and slow photon effects seem to be highly attractive for efficient use of incident photons. Therefore, the study on PCs-based plasmonic photocatalysts has been conducted, mainly on titania inverse opal (IO) modified with nanoparticles (NPs) of NM. Although, the research is quite new and only several reports have been published, it might be concluded that the matching between LSPR and PBG (especially at red edge) by tuning of NMNPs size and IO-void diameter, respectively, is the most crucial for the photocatalytic activity.

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MOCVD of High-K Dielectrics and Conductive Metal Nitride Thin Films

MRS Proceedings ◽

10.1557/proc-606-13 ◽

1999 ◽

Vol 606 ◽

Cited By ~ 1

Author(s):

Yoshihide Senzaki ◽

Richard F. Hamilton ◽

Kimberly G. Reid ◽

Christopher C. Hobbs ◽

Rama I. Hegdec ◽

...

Keyword(s):

Thin Films ◽

Liquid Mixture ◽

Xrd Analysis ◽

Tantalum Nitride ◽

High Deposition Rate ◽

Low Viscosity ◽

High K ◽

Liquid Injection ◽

Direct Liquid Injection ◽

Deposited Films

AbstractA known liquid mixture of [(CH3CH2)2N]3 Ta=NCH2CH3 and [(CH3CH2)2N]3Ta[ð2-CH3CH2N=CH(CH3)] was studied to deposit Ta2O5 and TaN thin films by CVD. Films were deposited at temperatures below 400°C using oxygen for oxide and ammonia for nitride, respectively. XRD analysis revealed that as-deposited amorphous tantalum oxide films were converted to hexagonal Ta2O5 after annealing under oxygen, while tantalum nitride thin films contained cubic TaN as deposited. The low viscosity, thermal stability, and sufficient volatility of the precursor allows direct liquid injection to deliver the precursor, which results in high deposition rate and uniformity of the deposited films.

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Two-Step Synthesis of Ca-Based MgO Hybrid Adsorbent for Potential CO2 Capturing Application

Materials Science Forum ◽

10.4028/www.scientific.net/msf.981.369 ◽

2020 ◽

Vol 981 ◽

pp. 369-374

Author(s):

Farah Diana Mohd Daud ◽

Nurul Amirah Izzati Ahmad ◽

Mudrikah Sofia Mahmud ◽

Norshahida Sariffudin ◽

Hafizah Hanim Mohd Zaki

Keyword(s):

Carbon Capture ◽

Carbon Capture And Storage ◽

Xrd Analysis ◽

Magnesium Nitrate ◽

Synthesis Methods ◽

Step Method ◽

Support Materials ◽

Solid Sorbents ◽

The Stability ◽

Adsorption Desorption

Carbon capture and storage (CCS) is one of the method in reducing carbon dioxide (CO2) emissions into the atmosphere. CO2 capturing using calcium oxide (CaO) solid sorbents has been considered as an advanced concept for CO2 capture and recovery. However, the adsorption capacity of CaO decreases during repeated adsorption/desorption cycles. The stability of Ca-based sorbents during cyclic runs can be achieved via the incorporation of inert support materials. Among the available inert materials, MgO is most promising for CO2 due to high stability and a high Tammann temperature. Most of Ca- based MgO hybrid adsorbent synthesis methods sorbent come with its own limitations which are longer synthesis duration and complex or multistep methods. In this research, Ca-based MgO hybrid adsorbent was prepared via two-step method. Calcium acetate and magnesium nitrate as precursor had dissolved in water, follow by addition of ethanol. The mixture then became gelated and proceeded for calcination at 550°C and 650°C. The prepared sorbent was characterized by Scanning Electron Microscope (SEM), X-Ray Diffraction (XRD) and fourier transfer infrared spectroscopy (FTIR). The XRD analysis of the Ca-based MgO hybrid adsorbent showed the existence of MgO,CaO and CaCO3. FTIR analysis showed presence of Ca─O bond and Mg═O bond. The morphology of the hybrid adsorbent was found to be spherical to granular shape and agglomerated. The Ca- based MgO hybrid adsorbent structural and morphological shows great potential for CO2 capturing capacity over multiple carbonation cycles for CO2 capturing application.

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Preparation and Characterization of Ga2xIn2(1-x)O3 Films Deposited on α-Al2O3 (0001) by MOCVD

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.79-82.1535 ◽

2009 ◽

Vol 79-82 ◽

pp. 1535-1538

Author(s):

Ling Yi Kong ◽

Fan Yang ◽

Jin Ma ◽

Cai Na Luan ◽

Zhen Zhu

Keyword(s):

Thin Films ◽

Chemical Vapor ◽

Xrd Analysis ◽

Atomic Ratio ◽

Visible Range ◽

Electrical And Optical Properties ◽

Average Transmittance ◽

Gallium Content

Ga2xIn2(1-x)O3 thin films with different gallium content x [x = Ga/(Ga+In) atomic ratio] have been prepared on -Al2O3 (0001) substrates at 650°C by metalorganic chemical vapor deposition (MOCVD). Structural, electrical and optical properties of these films have been investigated in detail. The XRD analysis revealed that, as the gallium content increased, the crystalline quality of the films decreased. The highest Hall mobility of the films was 41.32 cm2v−1s−1. The absolute average transmittance of the Ga2xIn2(1-x)O3 thin films in the visible range exceeded 91%. The band gap could be tuned from 3.59 to 4.87 eV as gallium content increased.

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Extraction–Pyrolytic Method for TiO2 Polymorphs Production

Crystals ◽

10.3390/cryst11040431 ◽

2021 ◽

Vol 11 (4) ◽

pp. 431

Author(s):

Vera Serga ◽

Regina Burve ◽

Aija Krumina ◽

Marina Romanova ◽

Eugene A. Kotomin ◽

...

Keyword(s):

Titanium Dioxide ◽

Xrd Analysis ◽

Nanocrystalline Powders ◽

Precipitation Method ◽

Synthesis Methods ◽

Scanning Calorimetry ◽

Nanocrystalline Tio2 ◽

Organic Impurities ◽

Transmission Electron ◽

The Fourier Transform

The unique properties and numerous applications of nanocrystalline titanium dioxide (TiO2) are stimulating research on improving the existing and developing new titanium dioxide synthesis methods. In this work, we demonstrate for the first time the possibilities of the extraction–pyrolytic method (EPM) for the production of nanocrystalline TiO2 powders. A titanium-containing precursor (extract) was prepared by liquid–liquid extraction using valeric acid C4H9COOH without diluent as an extractant. Simultaneous thermogravimetric analysis and differential scanning calorimetry (TGA–DSC), as well as the Fourier-transform infrared (FTIR) spectroscopy were used to determine the temperature conditions to fabricate TiO2 powders free of organic impurities. The produced materials were also characterized by X-ray diffraction (XRD) analysis and transmission electron microscopy (TEM). The results showed the possibility of the fabrication of storage-stable liquid titanium (IV)-containing precursor, which provided nanocrystalline TiO2 powders. It was established that the EPM permits the production of both monophase (anatase polymorph or rutile polymorph) and biphase (mixed anatase–rutile polymorphs), impurity-free nanocrystalline TiO2 powders. For comparison, TiO2 powders were also produced by the precipitation method. The results presented in this study could serve as a solid basis for further developing the EPM for the cheap and simple production of nanocrystalline TiO2-based materials in the form of doped nanocrystalline powders, thin films, and composite materials.

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Morphological, Electrical and Optical Properties of Al-Doped Zinc Oxide Nanorods

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1110.218 ◽

2015 ◽

Vol 1110 ◽

pp. 218-221 ◽

Cited By ~ 2

Author(s):

R.R. Kothawale ◽

R.M. Mohite

Keyword(s):

Zinc Oxide ◽

Optical Properties ◽

Zno Nanorods ◽

Resistivity Measurement ◽

Xrd Analysis ◽

Zinc Oxide Nanorods ◽

Electrical Resistivity Measurement ◽

Potential Candidate ◽

Electrical And Optical Properties ◽

Oxide Nanorods

We have studied the structural, electrical and optical properties of Al-doped Zinc Oxide (ZnO) nanostructures deposited on glass substrate by chemical bath deposition method. Scanning electrom microscope images clearly reveal that AZO nanorods were successfully grown. The XRD analysis indicates that polycrystalline nature of ZnO nanorods. The calculated grain size is about 84 nm. Electrical resistivity measurement study showes the minimum d.c. resistivity of 3.216×10-4 Ω.cm was obtained for the AZO films sintered at 300°C. It gives AZO can be adopted as a transparant conductive oxide (TCO) material. Optical transmission spectra showes that more than 80% transmission and 3.47 eV optical band gap of harvested AZO films. It is a potential candidate for ligth emitting diodes (LEDs), photonic crystals, TCO and photovoltaic application.

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Evaluation of Cytotoxic Effect of Silver Nanoparticles (AgNP) Synthesized from Phlebodium aureum (L.) J. Smith Extracts

Anti-Cancer Agents in Medicinal Chemistry ◽

10.2174/1871520621999201230233408 ◽

2020 ◽

Vol 21 ◽

Author(s):

Johnson Marimuthu ◽

Shibila Thangaiah ◽

Amutha Santhanam ◽

Vidyarani George

Keyword(s):

Silver Nanoparticles ◽

Green Synthesis ◽

Large Scale ◽

Color Change ◽

Nanoparticle Synthesis ◽

Xrd Analysis ◽

Nano Particles ◽

Synthesis Methods ◽

Aqueous Extracts ◽

Ft Ir

Background:: Chemical synthesis methods are adverse in the medicinal field as they produce toxic in the surface whereas green synthesis provide advancement as well as they are cost effective, environment friendly, can be easily scaled up for large scale synthesis. Silver and silver nanoparticles have an important application in the medical industry such as tropical ointments which are used to prevent infection against burn and open wounds. There is no report on the green synthesis from Phlebodium aureum (L.) J. Smith. Objective:: The present study was aimed to synthesize silver nano-particles using Phlebodium aureum (L.) J. Smith extracts by green approach and to screen their cytotoxicity. Methods:: The synthesized AgNPs of P. aureum were characterized by FT-IR, SEM and XRD. The cytotoxicity of the aqueous extracts and AgNPs of P. aureum were determined. Results:: The silver nanoparticle synthesis was confirmed by color change from yellow to dark brown and absorption peak at 460 nm. FT-IR analysis confirmed the capping by proteins and other metabolites. XRD analysis confirmed the existence of silver nanaoparticles with a peak at 46.253°. The dose dependent cytotoxicity was observed in the aqueous and silver nanoparticles of P.aureum. Conclusion:: The present study gave a simple and cheap route to synthesize the AgNPs using aqueous extracts of P. aureum. The studied extracts of P. aureum can be considered as a promising candidate for a plant-derived anti-tumour compound.

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Green Synthesis of Zirconia (ZrO2) Nanoparticles using Curcuma Longa Extract and Investigation of Compressive Strength of Epoxy resin (EP)/ZrO2 Nanocomposites

Journal of Nepal Chemical Society ◽

10.3126/jncs.v42i1.35328 ◽

2021 ◽

Vol 42 (1) ◽

pp. 45-50

Author(s):

Manish Bishwokarma ◽

Arun Bhujel ◽

Manish Baskota ◽

Rajesh Pandit

Keyword(s):

Compressive Strength ◽

Epoxy Resin ◽

Curcuma Longa ◽

Xrd Analysis ◽

Zro2 Nanoparticles ◽

Size Analysis ◽

Synthesis Methods ◽

Spectra Analysis ◽

Wide Range ◽

Polymorphic Materials

Zirconia (ZrO2) nanoparticles are polymorphic materials having a wide range of applications. It can be synthesized via green as well as chemical synthesis methods. In this work, ZrO2 nanoparticles were synthesized by the green method using Curcuma longa extract. Curcuma longa extract was prepared using the standard method. The synthesized ZrO2 was characterized by the X-ray diffraction (XRD) analysis and Fourier transform infra-red (FTIR) spectroscopy for their structural and size analysis. The analysis of the XRD pattern of ZrO2 showed the tetragonal phase structure and the size was calculated using the Debye Scherrer equation which was about 34.55 nm. The FTIR spectra analysis showed a broad absorption peak particularly at about 774 cm-1 and about 499 cm-1 correspondings to Zr-O2-Zr asymmetric and Zr-O stretching modes, respectively. The characterized ZrO2 nanoparticles were used for the preparation of epoxy resin/ZrO2 nanocomposites. The compressive strength of pure epoxy resin and epoxy resin/ZrO2 nanocomposites were measured by a compressive strength tester and the result indicates the high amount of zirconia was not suitable for the nanocomposites.

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