Growth and Characterization of Iron Nanoparticle Catalysts for Nanomaterial Synthesis

2008 ◽  
Author(s):  
Jeffrey J. Lombardo ◽  
Andrew C. Lysaght ◽  
Daniel G. Goberman ◽  
Wilson K. S. Chiu
Keyword(s):  
Photoelectron Spectroscopy ◽  
Particle Deposition ◽  
Deposition Time ◽  
Xps Spectra ◽  
Single Walled Carbon Nanotube ◽  
Force Microscopy ◽  
Nanoparticle Catalysts ◽  
Atomic Force ◽  
Fe Nanoparticles ◽  
Quartz Substrates

The properties and structure of nanoscale particles can vary widely from their bulk counterparts. In order to use nanoparticles effectively one must first have an understanding of their composition. In this study, Fe nanoparticles were grown on fused quartz substrates using a method that allows for varying particle size and surface coverage by altering the particle deposition time. The resulting particles were analyzed using x-ray photoelectron spectroscopy (XPS) in order to understand how nanoparticle composition evolves as a function of deposition time. In addition, atomic force microscopy (AFM) was used to correlate the changes in size and surface density of the Fe particles with the changes in the XPS spectra as deposition time was varied. Knowledge gained through this study will be used to optimize the growth of Fe nanoparticles for single-walled carbon nanotube (SWNT) synthesis.

CHEMICAL COMPOSITION STUDY OF VANADIUM PENTOXIDE XEROGELS DOPED BY BOVINE ALBUMIN

2016 ◽  
Vol 23 (06) ◽  
pp. 1650058
Author(s):  
R. SEREIKA ◽  
S. KACIULIS ◽  
A. MEZZI ◽  
M. BRUCALE
Keyword(s):  
Vanadium Pentoxide ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Thin Layers ◽  
Xps Spectra ◽  
Force Microscopy ◽  
Molar Ratios ◽  
Atomic Force ◽  
Protonated Amine ◽  
Vanadium Ions

Metal–bioorganic compounds of vanadium pentoxide and bovine serum albumin (BSA) (Fraction V) were obtained by using sol–gel method. Series of the samples (BSA)xV2O[Formula: see text]H2O, where [Formula: see text], 0.01 and 0.001, were originally produced by the synthesis of vanadium pentoxide xerogels and subsequent blending with water-dissolved BSA in appropriate molar ratios. It was evident that the gelation process does not occur for [Formula: see text]. For the X-ray photoelectron spectroscopy (XPS) studies, the thin layers of these materials were prepared by drying the gel onto the glass and mica substrates. The surface morphology of the samples was characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques. It follows from the analysis of experimental XPS spectra of (BSA)xV2O[Formula: see text]H2O that the nitrogen ions in pure albumin and in (BSA)[Formula: see text]V2O[Formula: see text]H2O are present in imine, amine and protonated amine groups. The additional protonated amine arises when the concentration of albumin in (BSA)xV2O[Formula: see text]H2O is low ([Formula: see text]). Increasing the amount of albumin results in decrease of the number of oxygen ions bonded to vanadium. At the same time (with increase of albumin), the component of oxygen bounded to carbon and nitrogen is increasing. In the samples with greater amount of albumin, the reduction of vanadium ions occurs. This means that the trivalent and tetravalent vanadium ions are present together with pentavalent ones.

scholarly journals Effects of Deposition Time on the Morphology, Structure, and Optical Properties of PbS Thin Films Prepared by Chemical Bath Deposition

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
B. Abdallah ◽  
A. Ismail ◽  
H. Kashoua ◽  
W. Zetoun
Keyword(s):  
Thin Films ◽  
Chemical Bath Deposition ◽  
Photoelectron Spectroscopy ◽  
Deposition Time ◽  
Optical Band Gap ◽  
Optical Transmittance ◽  
Xrd Analysis ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force

Lead sulfide thin films were prepared by chemical bath deposition (CBD) on both glass and Si (100) substrates. XRD analysis of the PbS film deposited at 25°C showed that the prepared films have a polycrystalline structure with (200) preferential orientation. Larger grains could be obtained by increasing the deposition time. The prepared films were also chemically characterized using X-ray photoelectron spectroscopy (XPS), which confirmed the presence of lead and sulfur as PbS. While energy dispersive X-ray spectroscopy (EDX) technique was used to verify the stoichiometry of the prepared films. Atomic force microscopy (AFM) was used to study the change in the films’ morphology with the deposition time. The effect of the deposition time, on both optical transmittance in the UV-Vis-NIR region and the structure of the film, was studied. The obtained results demonstrated that the optical band gap decreased when the thickness increased.

Atomic Force Microscopy and X-Ray Photoelectron Spectroscopy Study on the Surface and Interface States of Liq and ITO Films

2010 ◽  
Vol 152-153 ◽  
pp. 566-571
Author(s):  
Jian Feng Li ◽  
Qing Song ◽  
Wei Bing Shi ◽  
Fu Jia Zhang
Keyword(s):  
Atomic Force Microscopy ◽  
Indium Tin Oxide ◽  
Photoelectron Spectroscopy ◽  
Interface States ◽  
Xps Spectra ◽  
X Ray ◽  
Force Microscopy ◽  
Surface And Interface ◽  
Atomic Force ◽  
Blue Electroluminescent Material

An understanding of the surface and interface states of the organic material and the underlying andoe material is meaningful for organic light-emitting devices (OLEDs). The 8-Hydroxyquinolinolatolithium (Liq) was deposited on indium-tin-oxide (ITO) coated glass by traditional vacuum evaporation.The thickness of Liq is about 120nm. The morphology, surface and interface electron states of the Liq and the underlying ITO have been investigated with the utilization of the atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) technology. AFM observation indicated that Liq grows in the shape of an asymmetrically-distributed island, with each island resembling a round hillock and different size. The Liq film is not very uniform and teemed with many pinholes and cracks.The analysis on XPS spectra of the surface of the Liq/ITO samples shows that, the core-levels of Li1s, C1s, N1s, O1s, In3d5/2, and Sn3d5/2, spectra slightly shift towards lower binding energy with the increase of the sputtering time, which may be caused by the effect of oxygen, indium and tin in ITO diffusing into Liq layer and the argon ions beam with energy. Coordination bond between Li atoms and N atoms does not exist in Liq, which is the main reason why Liq is the blue electroluminescent material. The C atoms mainly bond to C, N and O atoms, forming C-C, C-N=C and C-O bonds, respectively. And there is a speculation of the existence of contaminated C atoms in the surface of ITO, while the O atoms basically originate from quinolate rings and the absorption of O2 and H2O. At the interface N and O, In and Sn interact to some extent, which probably affects the emitting colour of Liq based OLEDs. The analysis of surface of In3d and Sn3d spectrum by XPS provides additional evidence of the existence of cracks and pinholes in Liq layer, leading to much absorption of air molecules.

scholarly journals Growth and Characterization of Nanostructured TiCrN Films Prepared by DC Magnetron Cosputtering

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Chutima Paksunchai ◽  
Somyod Denchitcharoen ◽  
Surasing Chaiyakun ◽  
Pichet Limsuwan
Keyword(s):  
Photoelectron Spectroscopy ◽  
Columnar Structure ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
Xps Spectra ◽  
X Ray ◽  
Force Microscopy ◽  
Conduction Bands ◽  
Atomic Force ◽  
Unbalanced Magnetron

Nanostructured TiCrN films were grown on Si (100) wafers by reactive DC unbalanced magnetron cosputtering technique without external heating and voltage biasing to the substrates. The effects of Ti sputtering current on the chemical composition, chemical state, electronic structure, crystal structure, and morphology of the TiCrN films were characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), atomic force microscopy (AFM), and field emission scanning electron microscopy (FE-SEM), respectively. The results showed that all prepared films were formed as an understoichiometric (Ti, Cr)N solid solution with the fcc B1 type phase. The films exhibited a nanostructure with a crystallite size of less than 14 nm. The deconvolution of XPS spectra revealed the chemical bonding between Ti, Cr, N, and O elements. The addition of Ti contents led to the decrease of valence electrons filled in the d conduction bands which result in the change of binding energy of electrons in core levels. The roughness of the films was found to increase with increasingITi. The cross-sectional morphology of the films showed columnar structure with dome tops.

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 Photocatalytic reduction of graphene oxide with cuprous oxide film under UV-vis irradiation

2020 ◽  
Vol 59 (1) ◽  
pp. 207-214 ◽  
Author(s):  
Yao Wang ◽  
Jianqing Feng ◽  
Lihua Jin ◽  
Chengshan Li
Keyword(s):  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Low Cost ◽  
Photocatalytic Reduction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Reduced Graphene ◽  
Reduction Efficiency ◽  
Metal Organic ◽  
Reduction Effect

AbstractWe have grown Cu2O films by different routes including self-oxidation and metal-organic deposition (MOD). The reduction efficiency of Cu2O films on graphene oxide (GO) synthesized by modified Hummer’s method has been studied. Surface morphology and chemical state of as-prepared Cu2O film and GO sheets reduced at different conditions have also been investigated using atomic force microscopy (AFM) and x-ray photoelectron spectroscopy (XPS). Results show that self-oxidation Cu2O film is more effective on phtocatalytic reduction of GO than MOD-Cu2O film. Moreover, reduction effect of self-oxidation Cu2O film to GO is comparable to that of environmental-friendly reducing agent of vitamin C. The present results offer a potentially eco-friendly and low-cost approach for the manufacture of reduced graphene oxide (RGO) by photocatalytic reduction.

scholarly journals Interface Structures and Electronic States of Epitaxial Tetraazanaphthacene on Single-Crystal Pentacene

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1088
Author(s):  
Yuki Gunjo ◽  
Hajime Kamebuchi ◽  
Ryohei Tsuruta ◽  
Masaki Iwashita ◽  
Kana Takahashi ◽  
...  
Keyword(s):  
Single Crystal ◽  
Photoelectron Spectroscopy ◽  
Grazing Incidence ◽  
Force Microscopy ◽  
Interface Dipole ◽  
Atomic Force ◽  
Interfacial Structures ◽  
Donor And Acceptor ◽  
A Charge ◽  
Interface Structures

The structural and electronic properties of interfaces composed of donor and acceptor molecules play important roles in the development of organic opto-electronic devices. Epitaxial growth of organic semiconductor molecules offers a possibility to control the interfacial structures and to explore precise properties at the intermolecular contacts. 5,6,11,12-tetraazanaphthacene (TANC) is an acceptor molecule with a molecular structure similar to that of pentacene, a representative donor material, and thus, good compatibility with pentacene is expected. In this study, the physicochemical properties of the molecular interface between TANC and pentacene single crystal (PnSC) substrates were analyzed by atomic force microscopy, grazing-incidence X-ray diffraction (GIXD), and photoelectron spectroscopy. GIXD revealed that TANC molecules assemble into epitaxial overlayers of the (010) oriented crystallites by aligning an axis where the side edges of the molecules face each other along the [1¯10] direction of the PnSC. No apparent interface dipole was found, and the energy level offset between the highest occupied molecular orbitals of TANC and the PnSC was determined to be 1.75 eV, which led to a charge transfer gap width of 0.7 eV at the interface.

scholarly journals Silane-Coating Strategy for Titanium Functionalization Does Not Impair Osteogenesis In Vivo

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1814
Author(s):  
Plinio Mendes Senna ◽  
Carlos Fernando de Almeida Barros Mourão ◽  
Rafael Coutinho Mello-Machado ◽  
Kayvon Javid ◽  
Pietro Montemezzi ◽  
...  
Keyword(s):  
Bone Formation ◽  
Photoelectron Spectroscopy ◽  
Titanium Surface ◽  
Rabbit Model ◽  
Biologically Active ◽  
Force Microscopy ◽  
Atomic Force ◽  
Silane Coating ◽  
Titanium Screws

Silane-coating strategy has been used to bind biological compounds to the titanium surface, thereby making implant devices biologically active. However, it has not been determined if the presence of the silane coating itself is biocompatible to osseointegration. The aim of the present study was to evaluate if silane-coating affects bone formation on titanium using a rabbit model. For this, titanium screw implants (3.75 by 6 mm) were hydroxylated in a solution of H2SO4/30% H2O2 for 4 h before silane-coating with 3-aminopropyltriethoxysilane (APTES). A parallel set of titanium screws underwent only the hydroxylation process to present similar acid-etched topography as a control. The presence of the silane on the surface was checked by x-ray photoelectron spectroscopy (XPS), with scanning electron microscopy (SEM) and atomic force microscopy (AFM). A total of 40 titanium screws were implanted in the tibia of ten New Zealand rabbits in order to evaluate bone-to-implant contact (BIC) after 3 weeks and 6 weeks of healing. Silane-coated surface presented higher nitrogen content in the XPS analysis, while micro- and nano-topography of the surface remained unaffected. No difference between the groups was observed after 3 and 6 weeks of healing (p > 0.05, independent t-test), although an increase in BIC occurred over time. These results indicate that silanization of a titanium surface with APTES did not impair the bone formation, indicating that this can be a reliable tool to anchor osteogenic molecules on the surface of implant devices.

scholarly journals Change in Interface Characteristics of ITO Modified with n-decyltrimethoxysilane

Crystals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 645
Author(s):  
Myung-Gyun Baek ◽  
Johng-Eon Shin ◽  
Dong-Hyun Hwang ◽  
Sung-Hoon Kim ◽  
Hong-Gyu Park ◽  
...  
Keyword(s):  
Contact Angle ◽  
Work Function ◽  
Indium Tin Oxide ◽  
Photoelectron Spectroscopy ◽  
Deposition Time ◽  
Interfacial Properties ◽  
Average Roughness ◽  
Light Emitting ◽  
Force Microscopy ◽  
Angle Measurements

Herein, we examined changes in the interfacial properties of organic light-emitting diodes when n-decyltrimethoxysilane (CH3SAM) was deposited on the surface of an indium tin oxide (ITO) electrode for various deposition times. It was revealed that the interfacial properties varied with deposition time. As the latter increased, so did the measured value of the contact angle, and ITO substrate exhibited a lower wettability. The contact angle measurements for bare ITO at 1, 10, 30, and 90 min were 57.41°, 63.43°, 73.76°, 81.47°, respectively, and the highest value obtained was 93.34°. In addition, the average roughness and work function of the ITO were measured using atomic force microscopy and X-ray photoelectron spectroscopy. As the deposition time of CH3SAM on the ITO substrates increased, it was evident that the former was well aligned with the latter, improving surface modification. The work function of CH3SAM, modified on the ITO substrates, improved by approximately 0.11 eV from 5.05–5.16 eV. The introduction of CH3SAM to the ITO revealed the ease of adjustment of the characteristics of ITO substrates.

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