scholarly journals Corrosion Behavior and Mechanism of Carbon Ion-Implanted Magnesium Alloy

Coatings ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 734
Author(s):  
Banglong Yu ◽  
Jun Dai ◽  
Qingdong Ruan ◽  
Zili Liu ◽  
Paul K. Chu
Keyword(s):  
Electron Microscopy ◽  
Magnesium Alloy ◽  
Ion Implantation ◽  
Electron Energy ◽  
Photoelectron Spectroscopy ◽  
Density Functional ◽  
Electronic Density ◽  
Carbon Ion ◽  
X Ray ◽  
Ion Implanted

Carbon ion implantation was conducted on an AM60 magnesium alloy with fluences between 1 × 1016 and 6 × 1016 ions/cm2 and an energy of 35 keV. The microstructure and electrochemical properties of the samples were systematically characterized by X-ray photoelectron spectroscopy, X-ray diffraction, Raman scattering, scanning electron microscopy, transmission electron microscopy, and electrochemical methods. These studies reveal that a 250 nm-thick C-rich layer is formed on the surface and the Mg2C3 phase embeds in the ion-implanted region. The crystal structure of the Mg2C3 was constructed, and an electronic density map was calculated by density-functional theory calculation. The large peak in the density of states (DOS) shows two atomic p orbitals for Mg2C3. The main electron energy is concentrated between −50 and −40 eV, and the electron energy mainly comes from Mg (p) and Mg (s). The electrochemical experiments reveal that the Ecorr is −1.35 V and Icorr is 20.1 μA/cm2 for the sample implanted with the optimal fluence of 6 × 1016 ions/cm2. The sample from C ion implantation gives rise to better corrosion resistance.

scholarly journals Microstructure and Mechanical Properties of Ti + N Ion Implanted Cronidur30 Steel

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 427 ◽  
Author(s):  
Jie Jin ◽  
Wei Wang ◽  
Xinchun Chen
Keyword(s):  
Mechanical Properties ◽  
Ion Implantation ◽  
Photoelectron Spectroscopy ◽  
Structural Modification ◽  
Surface Region ◽  
Grazing Incidence ◽  
Bearing Steel ◽  
Near Surface ◽  
X Ray ◽  
Ion Implanted

In this study, Ti + N ion implantation was used as a surface modification method for surface hardening and friction-reducing properties of Cronidur30 bearing steel. The structural modification and newly-formed ceramic phases induced by the ion implantation processes were investigated by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and grazing incidence X-ray diffraction (GIXRD). The mechanical properties of the samples were tested by nanoindentation and friction experiments. The surface nanohardness was also improved significantly, changing from ~10.5 GPa (pristine substrate) to ~14.2 GPa (Ti + N implanted sample). The friction coefficient of Ti + N ion implanted samples was greatly reduced before failure, which is less than one third of pristine samples. Furthermore, the TEM analyses confirmed a trilamellar structure at the near-surface region, in which amorphous/ceramic nanocrystalline phases were embedded into the implanted layers. The combined structural modification and hardening ceramic phases played a crucial role in improving surface properties, and the variations in these two factors determined the differences in the mechanical properties of the samples.

NANOMECHANICAL AND CORROSION PROPERTIES OF ZK60 MAGNESIUM ALLOY IMPROVED BY GD ION IMPLANTATION

2014 ◽  
Vol 21 (06) ◽  
pp. 1450085 ◽  
Author(s):  
XUE WEI TAO ◽  
ZHANG ZHONG WANG ◽  
XIAO BO ZHANG ◽  
ZHI XIN BA ◽  
YA MEI WANG
Keyword(s):  
Magnesium Alloy ◽  
Ion Implantation ◽  
Photoelectron Spectroscopy ◽  
Surface Hardness ◽  
Protective Layer ◽  
Hybrid Structure ◽  
Nacl Solution ◽  
Corrosion Properties ◽  
X Ray ◽  
Zk60 Magnesium Alloy

Gadolinium ( Gd ) ion implantation with doses from 2.5 × 1016 to 1 × 1017 ions/cm2 into ZK60 magnesium alloy was carried out to improve its surface properties. X-ray photoelectron spectroscopy (XPS), nanoindenter, electrochemical workstation and scanning electron microscope (SEM) were applied to analyze the chemical composition, nanomechanical properties and corrosion characteristics of the implanted layer. The results indicate that Gd ion implantation produces a hybrid-structure protective layer composed of MgO , Gd 2 O 3 and metallic Gd in ZK60 magnesium alloy. The surface hardness and modulus of the Gd implanted magnesium alloy are improved by about 300% and 100%, respectively with the dose of 1 × 1017 ions/cm2, while the slowest corrosion rate of the magnesium alloy in 3.5 wt.% NaCl solution is obtained with the dose of 5 × 1016 ions/cm2.

scholarly journals Ethanol Sensing Properties and First Principles Study of Au Supported on Mesoporous ZnO Derived from Metal Organic Framework ZIF-8

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4352
Author(s):  
Yanli Kang ◽  
Lu Zhang ◽  
Wenhao Wang ◽  
Feng Yu
Keyword(s):  
Electron Microscopy ◽  
Field Emission ◽  
Adsorption Energy ◽  
Photoelectron Spectroscopy ◽  
Density Functional ◽  
Metal Organic Framework ◽  
X Ray ◽  
Metal Organic ◽  
Mesoporous Zno ◽  
Organic Framework

It is of great significance to develop ethanol sensors with high sensitivity and low detection temperature. Hence, we prepared Au-supported material on mesoporous ZnO composites derived from a metal-organic framework ZIF-8 for the detection of ethanol gas. The obtained Au/ZnO materials were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (SEM), field emission transmission electron microscopy (TEM) and nitrogen adsorption and desorption isotherms. The results showed that the Au/ZnO-1.0 sample maintains a three-dimensional (3D) dodecahedron structure with a larger specific surface area (22.79 m2 g−1) and has more oxygen vacancies. Because of the unique ZIF structure, abundant surface defects and the formation of Au-ZnO Schottky junctions, an Au/ZnO-1.0 sensor has a response factor of 37.74 for 100 ppm ethanol at 250 °C, which is about 6 times that of pure ZnO material. In addition, the Au/ZnO-1.0 sensor has good selectivity for ethanol. According to density functional theory (DFT) calculations, the adsorption energy of Au/ZnO for ethanol (−1.813 eV) is significantly greater than that of pure ZnO (−0.217 eV). Furthermore, the adsorption energy for ethanol is greater than that of other gases.

scholarly journals Effects of Ti, Ni, and Dual Ti/Ni Plasma Immersion Ion Implantation on the Corrosion and Wear Properties of Magnesium Alloy

Coatings ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 313
Author(s):  
Jun Dai ◽  
Zheng Liu ◽  
Banglong Yu ◽  
Qingdong Ruan ◽  
Paul K. Chu
Keyword(s):  
Magnesium Alloy ◽  
Ion Implantation ◽  
Photoelectron Spectroscopy ◽  
Wear Test ◽  
Corrosion And Wear ◽  
X Ray Diffraction ◽  
Wear Properties ◽  
X Ray ◽  
Bonding Properties ◽  
Plasma Immersion Ion Implantation

Ti, Ni, and Ti/Ni plasma immersion ion implantation is carried out on the AM60 magnesium alloy with a 6 × 1016 ions/cm2 fluence and energy of 35 keV. The corrosion and wear properties of the ion-implanted samples are determined systematically by X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy, electrochemical methods and wear tests. A Ni-rich layer composed of α-Mg, Ni2O3, and NiTi2 is formed on the surface after dual Ti/Ni ion implantation, and the ion implantation range is approximately 300 nm. The corrosion resistance of the Ni- and Ti/Ni-implanted AM60 samples is significantly reduced in the 3.5% NaCl solution. However, NiTi2 does not adhere well to the grinding ring during the wear test due to the bonding properties, and the sample implanted with both Ti and Ni shows the best wear resistance.

scholarly journals Composites of Platinum-Iridium Alloy Nanoparticles and Graphene Oxide for the Dimethyl Amine Borane (DMAB) dehydrogenation at ambient conditions: An Experimental and Density Functional Theory Study

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Betül Sen ◽  
Ayşenur Aygun ◽  
Aysun Şavk ◽  
Mehmet Harbi Çalımlı ◽  
Mehmet Ferdi Fellah ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Density Functional ◽  
Catalyst Activity ◽  
Alloy Nanoparticles ◽  
Ambient Conditions ◽  
X Ray ◽  
Transmission Electron

Abstract In this paper, we present the synthesis, characterization, catalytic and computational studies of Composites of Platinum-Iridium Alloy Nanoparticles and Graphene Oxide (PtIr@GO) for dimethylamine borane (DMAB) dehydrogenation. The prepared PtIr@GO nanocatalysts were synthesized using an ethanol super-hydride method, and the characterization procedures for PtIr@GO alloy nanoparticles were carried out by various advanced spectroscopic methods like X-ray Diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Transmission Electron Microscopy(TEM) and high-resolution transmission electron microscopy (HRTEM). Additionally, catalytic activity, reusability, substrate concentration, and catalyst concentration experiments were performed for DMAB dehydrogenation catalyzed by PtIr@GO alloy nanomaterials. According to the results obtained in this study, PtIr@GO NPs catalyst was found to be active and reusable for the DMAB even at ambient conditions. Besides, DFT-B3LYP calculations have been utilized on PtIr@GO cluster to reveal the prepared catalyst activity. The calculated findings based on DFT was found to be a good agreement with experimental results.

Antibacterial silver-diatomite nanocomposite ceramic with low silver release

2019 ◽  
Vol 20 (2) ◽  
pp. 633-643
Author(s):  
Xiaopeng Qi ◽  
Junwei Chen ◽  
Qian Li ◽  
Hui Yang ◽  
Honghui Jiang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Water Treatment ◽  
Photoelectron Spectroscopy ◽  
Bactericidal Effect ◽  
Ceramic Filter ◽  
Ceramic Filters ◽  
X Ray ◽  
E Coli ◽  
Point Of Use ◽  
Silver Release

Abstract There is an urgent need for an effective and long-lasting ceramic filter for point-of-use water treatment. In this study, silver-diatomite nanocomposite ceramic filters were developed by an easy and effective method. The ceramic filters have a three-dimensional interconnected pore structure and porosity of 50.85%. Characterizations of the silver-diatomite nanocomposite ceramic filters were performed using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Silver nanoparticles were confirmed to be formed in situ in the ceramic filter. The highest silver concentration in water was 0.24 μg/L and 2.1 μg/L in short- and long-term experiments, indicating very low silver-release properties of silver-diatomite nanocomposite ceramic filter. The nanocomposite ceramics show strong bactericidal activity. When contact time with Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) of 105 colony forming units (CFU)/mL exceeded 3 h, the bactericidal rates of the four different silver content ceramics against E. coli and S. aureus were all 100%. Strong bactericidal effect against E. coli with initial concentration of 109 CFU/mL were also observed in ceramic newly obtained and ceramic immersed in water for 270 days, demonstrating its high stability. The silver-diatomite nanocomposite ceramic filters could be a promising candidate for point-of-use water treatment.

scholarly journals Phytosynthetic Fabrication of Lanthanum Ion-Doped Nickel Oxide Nanoparticles Using Sesbania grandiflora Leaf Extract and Their Anti-Microbial Properties

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 124
Author(s):  
Srihasam Saiganesh ◽  
Thyagarajan Krishnan ◽  
Golla Narasimha ◽  
Hesham S. Almoallim ◽  
Sulaiman Ali Alhari ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Optical Properties ◽  
Rare Earth ◽  
Nickel Oxide ◽  
Photoelectron Spectroscopy ◽  
Metal Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Nio Nanoparticles ◽  
X Ray ◽  
Sesbania Grandiflora

Over the past few years, the photogenic fabrication of metal oxide nanoparticles has attracted considerable attention, owing to the simple, eco-friendly, and non-toxic procedure. Herein, we fabricated NiO nanoparticles and altered their optical properties by doping with a rare earth element (lanthanum) using Sesbania grandiflora broth for antibacterial applications. The doping of lanthanum with NiO was systematically studied. The optical properties of the prepared nanomaterials were investigated through UV-Vis diffuse reflectance spectra (UV-DRS) analysis, and their structures were studied using X-ray diffraction analysis. The morphological features of the prepared nanomaterials were examined by scanning electron microscopy and transmission electron microscopy, their elemental structure was analyzed by energy-dispersive X-ray spectral analysis, and their oxidation states were analyzed by X-ray photoelectron spectroscopy. Furthermore, the antibacterial action of NiO and La-doped NiO nanoparticles was studied by the zone of inhibition method for Gram-negative and Gram-positive bacterial strains such as Escherichia coli and Bacillus sublitis. It was evident from the obtained results that the optimized compound NiOLa-04 performed better than the other prepared compounds. To the best of our knowledge, this is the first report on the phytosynthetic fabrication of rare-earth ion Lanthanum (La3+)-doped Nickel Oxide (NiO) nanoparticles and their anti-microbial studies.

scholarly journals Thermoelectric Generator Using Polyaniline-Coated Sb2Se3/β-Cu2Se Flexible Thermoelectric Films

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1518
Author(s):  
Minsu Kim ◽  
Dabin Park ◽  
Jooheon Kim
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Field Emission ◽  
Photoelectron Spectroscopy ◽  
Thermoelectric Generator ◽  
Hydrothermal Reaction ◽  
Water Evaporation ◽  
Pani Film ◽  
Portable Devices ◽  
X Ray

Herein, Sb2Se3 and β-Cu2Se nanowires are synthesized via hydrothermal reaction and water evaporation-induced self-assembly methods, respectively. The successful syntheses and morphologies of the Sb2Se3 and β-Cu2Se nanowires are confirmed via X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, field emission scanning electron microscopy (FE-SEM), and field emission transmission electron microscopy (FE-TEM). Sb2Se3 materials have low electrical conductivity which limits application to the thermoelectric generator. To improve the electrical conductivity of the Sb2Se3 and β-Cu2Se nanowires, polyaniline (PANI) is coated onto the surface and confirmed via Fourier-transform infrared spectroscopy (FT-IR), FE-TEM, and XPS analysis. After coating PANI, the electrical conductivities of Sb2Se3/β-Cu2Se/PANI composites were increased. The thermoelectric performance of the flexible Sb2Se3/β-Cu2Se/PANI films is then measured, and the 70%-Sb2Se3/30%-β-Cu2Se/PANI film is shown to provide the highest power factor of 181.61 μW/m·K2 at 473 K. In addition, a thermoelectric generator consisting of five legs of the 70%-Sb2Se3/30%-β-Cu2Se/PANI film is constructed and shown to provide an open-circuit voltage of 7.9 mV and an output power of 80.1 nW at ΔT = 30 K. This study demonstrates that the combination of inorganic thermoelectric materials and flexible polymers can generate power in wearable or portable devices.

scholarly journals Efficient Adsorption of Methylene Blue by Porous Biochar Derived from Soybean Dreg Using a One-Pot Synthesis Method

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 661
Author(s):  
Zhiwei Ying ◽  
Xinwei Chen ◽  
He Li ◽  
Xinqi Liu ◽  
Chi Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Methylene Blue ◽  
Photoelectron Spectroscopy ◽  
Synthesis Method ◽  
Urban Pollution ◽  
Maximum Adsorption Capacity ◽  
One Pot ◽  
Average Pore ◽  
X Ray ◽  
Isotherm Equation

Soybean dreg is a by-product of soybean products production, with a large consumption in China. Low utilization value leads to random discarding, which is one of the important sources of urban pollution. In this work, porous biochar was synthesized using a one-pot method and potassium bicarbonate (KHCO3) with low-cost soybean dreg (SD) powder as the carbon precursor to investigating the adsorption of methylene blue (MB). The prepared samples were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), elemental analyzer (EA), Brunauer-Emmett-Teller (BET), X-ray diffractometer (XRD), Raman spectroscopy (Raman), Fourier transform infrared spectrometer (FTIR), and X-ray photoelectron spectroscopy (XPS). The obtained SDB-K-3 showed a high specific surface area of 1620 m2 g−1, a large pore volume of 0.7509 cm3 g−1, and an average pore diameter of 1.859 nm. The results indicated that the maximum adsorption capacity of SDB-K-3 to MB could reach 1273.51 mg g−1 at 318 K. The kinetic data were most consistent with the pseudo-second-order model and the adsorption behavior was more suitable for the Langmuir isotherm equation. This study demonstrated that the porous biochar adsorbent can be prepared from soybean dreg by high value utilization, and it could hold significant potential for dye wastewater treatment in the future.

scholarly journals Investigation of Spin Coating Cerium-Doped Hydroxyapatite Thin Films with Antifungal Properties

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 464
Author(s):  
Simona Liliana Iconaru ◽  
Mihai Valentin Predoi ◽  
Patrick Chapon ◽  
Sofia Gaiaschi ◽  
Krzysztof Rokosz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Spin Coating ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
X Ray ◽  
Antifungal Properties ◽  
Scanning Electron

In this study, the cerium-doped hydroxyapatite (Ca10−xCex(PO4)6(OH)2 with xCe = 0.1, 10Ce-HAp) coatings obtained by the spin coating method were presented for the first time. The stability of the 10Ce-HAp suspension particles used in the preparation of coatings was evaluated by ultrasonic studies, transmission electron microscopy (TEM), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The surface morphology of the 10Ce-HAp coating was studied by SEM and atomic force microscopy (AFM) techniques. The obtained 10Ce-HAp coatings were uniform and without cracks or unevenness. Glow discharge optical emission spectroscopy (GDOES) and X-ray photoelectron spectroscopy (XPS) were used for the investigation of fine chemical depth profiling. The antifungal properties of the HAp and 10Ce-HAp suspensions and coatings were assessed using Candida albicans ATCC 10231 (C. albicans) fungal strain. The quantitative antifungal assays demonstrated that both 10Ce-HAp suspensions and coatings exhibited strong antifungal properties and that they successfully inhibited the development and adherence of C. albicans fungal cells for all the tested time intervals. The scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) visualization of the C. albicans fungal cells adherence to the 10Ce-HAp surface also demonstrated their strong inhibitory effects. In addition, the qualitative assays also suggested that the 10Ce-HAp coatings successfully stopped the biofilm formation.

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