scholarly journals Effects of Four Carboxyl-Containing Additives on Imitation Gold Electroplating Cu-Zn-Sn Alloys in an HEDP System

2020 ◽  
Author(s):  
Lifeng Ding ◽  
Chongyan Chen ◽  
Qiang Li ◽  
Ruonan Wang ◽  
Qi Wang ◽  
...  
Keyword(s):  
Alloy Coating ◽  
Electrochemical Analysis ◽  
Complexing Agent ◽  
Complexation Reaction ◽  
Gold Plating ◽  
Anhydrous Sodium Carbonate ◽  
X Ray ◽  
Alloy Electrodeposition ◽  
Potassium Tartrate ◽  
Golden Yellow

The requirements for using noncyanide imitation gold plating as decorative electroplating are increasing; thus, continuously improving the quality of the coating of the imitation gold plating and optimizing the coating process have become the current priority. In this work, hydroxyethylidene diphosphonic acid (HEDP) was used as the main complexing agent, CuSO4·5H2O, ZnSO4·7H2O and NaSnO3·3H2O were the main salts, and NaOH and anhydrous sodium carbonate were used as the buffers to prepare the electroplating solution. Using sodium citrate (SC), sodium potassium tartrate (SS), sodium gluconate (SG), and glycerol (Gl) as four additives, the effects of the number of carboxyl groups on the properties of a Cu-Zn-Sn alloy coating were compared. The electrochemical analysis showed that Cu-Zn-Sn alloy codeposition occurred at -0.50 V vs. Hg|HgO. The scanning electron microscopy (SEM) results showed that the particle size of the coatings obtained with carboxyl-containing additives was more uniform than that obtained with the electroplating solution without additives. The X-ray fluorescence spectrometry (XRF) analysis revealed that the composition of the Cu-Zn-Sn alloy coating obtained by using SC as an additive in the electroplating solution was 89.75 wt% Cu, 9.61 wt% Zn, and 0.64 wt% Sn, and the color of the coating was golden yellow. The X-ray diffraction (XRD) pattern showed that the coating was a mixture of Cu, Cu5Zn8, CuSn, Cu6Sn5, and CuZn phases. The analysis of the electroplating solution by UV, IR and NMR spectroscopy methods indicates that the additives improve the coating by affecting the complexation reaction of metal ions. These results can provide technical and theoretical guidance for developing Cu-Zn-Sn ternary alloy electrodeposition technology with the new cyanide-free HEDP alkaline electroplating system.

The Structural, Magnetic and Optical Properties of Ni-Mg-Zn Ferrite Prepared With Different Complexing Agents via Sol-Gel Method

2021 ◽  
Author(s):  
Yanchun Zhang ◽  
Aimin Sun ◽  
Zhaxi Suonan
Keyword(s):  
Optical Properties ◽  
Electron Microscope ◽  
Sol Gel ◽  
Complexing Agents ◽  
Complexing Agent ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Zn Ferrite ◽  
Vis Spectroscopy

Abstract Different complexing agents were used to prepare Ni-Mg-Zn ferrite with the composition formula Ni0.2Mg0.2Zn0.6Fe2O4 via sol-gel method, which included citric acid, oxalic acid, egg white and EDTA. The Ni0.2Mg0.2Zn0.6Fe2O4 ferrite with no complexing agent was also prepared as a comparison. The chemical phases of samples were analyzed by the X-ray diffraction (XRD), which indicated that samples had spinel phase structure. The lattice constants of samples are in the range of 8.3980 ~ 8.4089 Å. The composition and structure were further studied by fourier transform infrared spectroscopy (FTIR). There were two typical characteristic bands related to the stretching vibrations of spinel ferrite in FTIR spectra. Scanning electron microscope (SEM) micrographs and transmission electron microscope (TEM) images showed that the particles have the shape of spherical cube. Energy dispersive spectrometer (EDS) analyzed the elements and ingredients of samples, which included Ni, Mg, Zn, Fe and O. X-ray photoelectron spectroscopy (XPS) is used to examine further the elemental composition and chemical state of sample prepared with EDTA as complexing agent. The optical properties of samples were investigated by photoluminescence spectra and UV-Vis spectroscopy. Vibrating sample magnetometer (VSM) was used to characterize magnetic properties, hysteresis loops revealed the ferrimagnetism behavior of prepared samples.

Preparation and Characterization of Pt/Superfine Mesocarbon Microbead Powers Electrocatalysts

2005 ◽  
Vol 3 (3) ◽  
pp. 358-360 ◽  
Author(s):  
Jia Rong-Li ◽  
Wang Cheng-Yang ◽  
Zhu Bin
Keyword(s):  
Reduction Method ◽  
Direct Methanol Fuel Cells ◽  
Electrochemical Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Platinum Particles ◽  
Platinum Electrocatalyst ◽  
Direct Methanol

Superfine mesocarbon microbead powders (SFMCMBs) as the new supports for platinum electrocatalysts were first investigated. The Pt∕SFMCMB electrocatalysts were prepared by an impregnation-reduction method, with hexachloroplatinic acid as the platinum precursor and formaldehyde as the reducing agent. The catalysts were characterized with x-ray diffraction (XRD), field emission gun transmission electron microscope (TEM), and electrochemical analysis. TEM photos showed the platinum particles were dispersed uniformly on the surface of SFMCMBs and there existed a little aggregation of platinum particles in the Pt∕SFMCMB catalysts. The TEM photos showed the existence of the platinum on the supports where the average platinum particle size were 4-6nm. The electrochemical analysis proved that SFMCMBs are excellent candidates to be used as the support of platinum electrocatalyst for methanol electrochemical oxidation as the potential catalyst candidate for direct methanol fuel cells (DMFCs).

Effect of Synthesis Conditions on the Structure and Electrochemical Properties of LiNi1/2Mn1/2O2 by Sol Gel Method

2011 ◽  
Vol 399-401 ◽  
pp. 1447-1450
Author(s):  
Zhi Yong Yu ◽  
Han Xing Liu
Keyword(s):  
Electrochemical Properties ◽  
Sol Gel ◽  
Electrochemical Analysis ◽  
X Ray Diffraction ◽  
Capacity Fading ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Synthesis Conditions ◽  
A Current

The layered LiNi1/2Mn1/2O2 cathode materials were synthesized by a sol gel method. The effects of calcination temperature and time on the structural and electrochemical properties of the LiNi1/2Mn1/2O2 were investigated. The prepared samples were characterized by X-ray diffraction (XRD) and electrochemical analysis. The results revealed that the layered LiNi1/2Mn1/2O2 material could be optimal synthesized at temperature of 900°C for 10h. The sample prepared under the above conditions has the highest initial discharge capacity of 151 mAh/g and showed no dramatic capacity fading during 20 cycles between 2.5-4.5V at a current rate of 20mA/g.

scholarly journals Organosilane-functionalization of nanostructured indium tin oxide films

2016 ◽  
Vol 6 (6) ◽  
pp. 20160056 ◽  
Author(s):  
R. Pruna ◽  
F. Palacio ◽  
M. Martínez ◽  
O. Blázquez ◽  
S. Hernández ◽  
...  
Keyword(s):  
Surface Area ◽  
Indium Tin Oxide ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Annealing Treatment ◽  
Electrochemical Analysis ◽  
Cyclic Voltammograms ◽  
X Ray ◽  
Chip Technology ◽  
Significant Difference

Fabrication and organosilane-functionalization and characterization of nanostructured ITO electrodes are reported. Nanostructured ITO electrodes were obtained by electron beam evaporation, and a subsequent annealing treatment was selectively performed to modify their crystalline state. An increase in geometrical surface area in comparison with thin-film electrodes area was observed by atomic force microscopy, implying higher electroactive surface area for nanostructured ITO electrodes and thus higher detection levels. To investigate the increase in detectability, chemical organosilane-functionalization of nanostructured ITO electrodes was performed. The formation of 3-glycidoxypropyltrimethoxysilane (GOPTS) layers was detected by X-ray photoelectron spectroscopy. As an indirect method to confirm the presence of organosilane molecules on the ITO substrates, cyclic voltammetry and electrochemical impedance spectroscopy (EIS) were also carried out. Cyclic voltammograms of functionalized ITO electrodes presented lower reduction-oxidation peak currents compared with non-functionalized ITO electrodes. These results demonstrate the presence of the epoxysilane coating on the ITO surface. EIS showed that organosilane-functionalized electrodes present higher polarization resistance, acting as an electronic barrier for the electron transfer between the conductive solution and the ITO electrode. The results of these electrochemical measurements, together with the significant difference in the X-ray spectra between bare ITO and organosilane-functionalized ITO substrates, may point to a new exploitable oxide-based nanostructured material for biosensing applications. As a first step towards sensing, rapid functionalization of such substrates and their application to electrochemical analysis is tested in this work. Interestingly, oxide-based materials are highly integrable with the silicon chip technology, which would permit the easy adaptation of such sensors into lab-on-a-chip configurations, providing benefits such as reduced size and weight to facilitate on-chip integration, and leading to low-cost mass production of microanalysis systems.

scholarly journals Caulerpa sertularioides extract as a complexing agent in the synthesis of ZnO and Zn(OH)2 nanoparticles and its effect in the azo dye’s photocatalysis in water

BioResources ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. 1548-1560
Author(s):  
Daniel Garcia-Bedoya ◽  
Luis P. Ramírez-Rodríguez ◽  
Jesús M. Quiroz-Castillo ◽  
Edgard Esquer-Miranda ◽  
Arnulfo Castellanos-Moreno
Keyword(s):  
Azo Dyes ◽  
Industrial Wastewater ◽  
Methanol Extract ◽  
Complexing Agent ◽  
X Ray Diffraction ◽  
X Ray ◽  
Environmental Consequences ◽  
Photocatalytic Effect ◽  
Transmission Electron ◽  
Vis Spectroscopy

Algae constitute a diverse group that is useful in many biotechnological areas. In this paper, the usefulness of Caulerpa sertularioides methanol extract in the synthesis of ZnO and Zn(OH)2 nanoparticles was explored. This work had two main objectives: (1) to use the extract in the synthesis as an organic harmless complexing agent, and (2) to enhance a photocatalytic effect over AZO dyes in wastewater from fabric industries without adding nanomaterial to the environment due to its toxicity. Caulerpa extract performed the expected complexing action, and nanoparticles were formed in a size range from 45 to 69 nm. X-ray diffraction analysis (XRD), transmission electron microscopy (TEM) and UV-Vis spectroscopy were used to characterize the system. It was demonstrated that the nanoparticles were useful to photocatalyst AZO dyes in the water, while contained in tetraethylorthosilicate composites. These could be used in industrial wastewater and are expected to have no environmental consequences because the composites do not add nanoparticles to the water.

scholarly journals Slow cooling of protein crystals

2009 ◽  
Vol 42 (5) ◽  
pp. 944-952 ◽  
Author(s):  
Matthew Warkentin ◽  
Robert E. Thorne
Keyword(s):  
Ice Nucleation ◽  
Glycerol Solution ◽  
X Ray Diffraction ◽  
Slow Cooling ◽  
Sodium Potassium ◽  
X Ray ◽  
Structure And Dynamics ◽  
Potassium Tartrate ◽  
Flash Cooling ◽  
Diffraction Patterns

Cryoprotectant-free thaumatin crystals have been cooled from 300 to 100 K at a rate of 0.1 K s−1– 103–104times slower than in conventional flash cooling – while continuously collecting X-ray diffraction data, so as to follow the evolution of protein lattice and solvent properties during cooling. Diffraction patterns show no evidence of crystalline ice at any temperature. This indicates that the lattice of protein molecules is itself an excellent cryoprotectant, and with sodium potassium tartrate incorporated from the 1.5 Mmother liquor ice nucleation rates are at least as low as in a 70% glycerol solution. Crystal quality during slow cooling remains high, with an average mosaicity at 100 K of 0.2°. Most of the mosaicity increase occurs above ∼200 K, where the solvent is still liquid, and is concurrent with an anisotropic contraction of the unit cell. Near 180 K a crossover to solid-like solvent behavior occurs, and on further cooling there is no additional degradation of crystal order. The variation ofBfactor with temperature shows clear evidence of a protein dynamical transition near 210 K, and at lower temperatures the slope dB/dTis a factor of 3–6 smaller than has been reported for any other protein. These results establish the feasibility of fully temperature controlled studies of protein structure and dynamics between 300 and 100 K.

scholarly journals Synergetic Effects of Temperature and Perpendicular Magnetic Field on Zn-Ni Alloy Electrodepositing Process

2021 ◽  
Vol 33 (11) ◽  
pp. 2839-2844
Author(s):  
N. Benachour ◽  
S. Chouchane ◽  
J.P. Chopart
Keyword(s):  
Nickel Alloys ◽  
Synergetic Effect ◽  
Electrochemical Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Acid Bath ◽  
Ni Alloy ◽  
Adsorbed Intermediate ◽  
Effects Of Temperature ◽  
Steel Substrates

The zinc-nickel alloys were electrodeposited on stainless steel substrates during a chloride acid bath. The electroplating processes were investigated under a moderate perpendicular magnetic flux at uncommon temperatures. The coatings obtained were characterized by scanning microscopy (SEM) including EDX and X-ray diffraction (XRD). Chronopotentiometric curves were additionally implemented for electrochemical analysis. Structural analysis revealed that the obtained alloys consisted of a mix of the homogeneous phase γ-Ni3Zn22 and α-Zn-Ni at 70 ºC. The alloys variations observed within the chemical composition, crystallographic phases and morphology of the alloys. It is often explained particularly, by the progressive hydrogen reaction and therefore the evolution of the adsorbed intermediate species. The synergetic effect was significant at 70 ºC within the 1T field, including the appearance of normal co-deposition.

Insights into the Electronic Structure of Fe Penta-Coordinated Complexes. Spectroscopic Examination and Electrochemical Analysis for the Oxygen Reduction and Oxygen Evolution Reactions.

2021 ◽  
Author(s):  
César Zúñiga-Loyola ◽  
Gabriel Abarca ◽  
Maria Soledad Ureta-Zanartu ◽  
Carolina Aliaga ◽  
Jose Zagal ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electronic Structure ◽  
Oxygen Reduction ◽  
Oxygen Evolution ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Analysis ◽  
X Ray ◽  
Spectroscopic Examination ◽  
Modified Carbon Nanotubes

Fe phthalocyanine was coordinated to pyridine-modified carbon nanotubes and studied as a catalyst for the oxygen reduction (ORR) and oxygen evolution reactions (OER). X-ray Photoelectron Spectroscopy (XPS), Mössbauer, and Electron...

scholarly journals Effect of Additives on Electrodeposition of Zinc-Nickel Alloy On Mild Steel

2019 ◽  
Vol 31 (4) ◽  
pp. 891-895
Author(s):  
Dinesh Kumar Chelike ◽  
K. Juliet Gnana Sundari
Keyword(s):  
Corrosion Resistance ◽  
Mild Steel ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Alloy Coating ◽  
Complexing Agent ◽  
Tafel Polarization ◽  
Good Corrosion Resistance ◽  
Ni Alloy ◽  
Strong Candidate

Considering the good corrosion resistance of Zn-Ni alloy, it is selected in the present study to be the protective coating on mild steel and it is considered as a strong candidate for the replacement of environmentally hazardous cadmium. Zn-Ni alloy coating is applied by electrodeposition at optimum temperature, current density and time. The bath solution used is consisting of EDTA as complexing agent. The electrodeposition is also carried out with tartaric acid and benzaldehyde additives to have good corrosion resistance and brightness. The electrodeposits obtained with and without additives are examined for nature and alloy composition. The corrosion behaviour of the electrodeposits is studied by Tafel polarization and electrochemical impedance spectroscopy.

Study on Manufacturing Process and Applying of Galvalume

2011 ◽  
Vol 704-705 ◽  
pp. 1406-1409
Author(s):  
Meng Song ◽  
Yun Li Feng ◽  
Jing Bo Yang
Keyword(s):  
Annealing Treatment ◽  
Alloy Coating ◽  
Alloy Layer ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Elongation ◽  
Coated Surface ◽  
Short Time ◽  
Zn Alloy ◽  
Thermal Simulation Experiment

Annealing and dip galvanizing treatments of Galvalume were studied by using methods of Gleeble thermal simulation experiment and optical microscopy (OM), scanning electronic microscopy (SEM), X-ray energy dispersive analysis (EDAX), X-ray diffraction (XRD) and so on. Meanwhile, surface morphology, microstructure, phases and the respective compositions of Al-Zn alloy coating plate were analyzed. The results show that decreased rate and prolonged time of annealing treatment cause less effect on process ability of product, which all because of the short time of annealing process in continuous aluminum-zinc treatment. However, coarse grain which causes low strength, high elongation and r value occurs when rising annealing temperature. To get better coated surface, in-zinc pot temperature should be controlled in the range of 590~610°C, and height of air-knife nozzle should be kept in the range of 150~200mm. Surface layer of 55％Al-Zn alloy coating is covered by Al-Zn alloy, the intermediate alloy layer is consisted of binary and ternary compounds, such as θ phase (FeAl3), Al0.3Fe3Si0.7 and Al3.21Si0.47. Keywords: Galvalume, Process, Microstructure, Properties

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