scholarly journals Calcined Co(II)-Triethylenetetramine, Co(II)- Polyaniline-Thiourea as the Cathode Catalyst of Proton Exchanged Membrane Fuel Cell

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3070
Author(s):  
Wen-Yao Huang ◽  
Li-Cheng Jheng ◽  
Tar-Hwa Hsieh ◽  
Ko-Shan Ho ◽  
Yen-Zen Wang ◽  
...  

Triethylenetetramine (TETA) and thiourea complexed Cobalt(II) (Co(II)) ions are used as cathode catalysts for proton exchanged membrane fuel cells (PEMFCs) under the protection of polyaniline (PANI) which can become a conducting medium after calcination. Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) spectra clearly reveal the presence of typical carbon nitride and sulfide bonds of the calcined Nitrogen (N)- or Sulfur (S)-doped co-catalysts. Clear (002) and (100) planes of carbon-related X-ray diffraction patterns are found for co-catalysts after calcination, related to the formation of a conducting medium after the calcination of PANI. An increasing intensity ratio of the D to G band of the Raman spectra reveal the doping of N and S elements. More porous surfaces of co-catalysts are found in scanning electronic microscopy (SEM) micropictures when prepared in the presence of both TETA and thiourea (CoNxSyC). Linear sweep voltammetry (LSV) curves show the highest reducing current to be 4 mAcm−2 at 1600 rpm for CoNxSyC, indicating the necessity for both N- and S-doping. The membrane electrode assemblies (MEA) prepared with the cathode made of CoNxSyC produces the highest maximum power density, close to 180 mW cm−2.

1994 ◽  
Vol 344 ◽  
Author(s):  
T. Sano ◽  
K. Akanuma ◽  
M. Tsuji ◽  
Y. Tamaura

AbstractOxygen-deficient magnetite (ODM; Fe3O4-δ, δ>0) synthesized by reduction of magnetite with H2 at 300°C decomposed CO2 to carbon with an efficiency of nearly 100% at 300°C. In this reaction, two oxygen ions of the CO2 were incorporated into the spinel structure of ODM and carbon was deposited on the surface of ODM with zero valence to form visible particles. The particles of carbon separated from ODM were studied by Raman, energy-dispersive X-ray and wave-dispersive X-ray spectroscopies. The carbon which had been deposited on the ODM was found to be a mixture of graphite and amorphous carbon in at least two levels of crystallization. X-ray photoelectron spectroscopy and X-ray diffraction patterns of the carbon-bearing magnetite (CBM) showed no indication of carbide (Fe3C) or metallic iron (α-Fe) phase formation. In the C 1s XPS spectra of the CBM, no peaks were observed which could be assigned to CO2 or CO. X-ray diffractometry, chemical analysis and TG-MS measurement showed that the carbon-bearing Ni(II)-ferrite (CBNF) (Ni(II)/Fetotal = 0.15) synthesized by the carbon deposition reaction from CO2 with the H2-reduced Ni(II)-ferrite was represented by (Ni0.28Fe2.72O4.00)1-δ (Ni2+06.9Fe2+2.31O3.00)δCτ (δ= 0.27, τ= 0.17). The carbon of the CBNF gave the CIOlayer-like oxide containing some Ni2+ ions.


2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Valentina Krylova ◽  
Mindaugas Andrulevičius

Copper sulfide layers were formed on polyamide PA 6 surface using the sorption-diffusion method. Polymer samples were immersed for 4 and 5 h in 0.15 mol⋅  solutions and acidified with HCl (0.1 mol⋅) at . After washing and drying, the samples were treated with Cu(I) salt solution. The samples were studied by UV/VIS, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) methods. All methods confirmed that on the surface of the polyamide film a layer of copper sulfide was formed. The copper sulfide layers are indirect band-gap semiconductors. The values of are 1.25 and 1.3 eV for 4 h and 5 h sulfured PA 6 respectively. Copper XPS spectra analyses showed Cu(I) bonds only in deeper layers of the formed film, while in sulfur XPS S 2p spectra dominating sulfide bonds were found after cleaning the surface with ions. It has been established by the XRD method that, beside , the layer contains as well. For PA 6 initially sulfured 4 h, grain size forchalcocite, , was  nm and fordjurleite, , it was 54.17 nm. The sheet resistance of the obtained layer varies from 6300 to 102 .


2015 ◽  
Vol 804 ◽  
pp. 97-103 ◽  
Author(s):  
Panakamon Deeyai ◽  
Thanapong Sareein ◽  
Bundit Putasaeng ◽  
Naphat Chathirat

Bulk Y2NiMnO6 samples were prepared by thermal decomposition technique at 800 °C for 6 hours. The effects of temperature on the structure of ceramics were investigated for different sintering temperatures in the range of 1000-1300 °C, while kept constant the sintering time of 12 hours. Structural characterization had been investigated via X-ray diffraction (XRD) on samples of different sintering temperatures. Results from the experiment had revealed that high temperature affected oxide in ceramic materials. Further analysis with X-ray photoelectron spectroscopy (XPS) technique had revealed an outstanding point of ceramics by investigating the Ni 2p, 2p3/2, Mn 2p1/2, 2p3/2, and Y 3d3/2, 3d5/2 at the surface of Y2NiMnO6 ceramics. The changes in relative intensity of XPS peaks and the shifts in their binding energy (eV) were observed in the results, while the effect of temperature on oxide in ceramics may be investigated with dielectric property in the future.


Clay Minerals ◽  
2012 ◽  
Vol 47 (3) ◽  
pp. 355-364 ◽  
Author(s):  
S. Fukuchi ◽  
M. Fukushima ◽  
R. Nishimoto ◽  
G. Qi ◽  
T. Sato

AbstractTo enhance the catalytic activities of zeolites for the polycondensation reactions of humic precursors, Fe was loaded into a zeolite via an ion-exchange reaction and the resulting product was subjected to calcination at 773 K. Two types iron-loaded zeolites were prepared using one equivalent (Fe-Z-1) and 10-equivalents (Fe-Z-10) of Fe2+ to the cation-exchange capacity of a natural zeolite from Niki town (Hokkaido, Japan). X-ray diffraction (XRD) patterns and X-ray photoelectron spectroscopy (XPS) spectra showed that the Fe(II) that was originally loaded into the cation-exchange sites in the zeolite became oxidized to a Fe(III) ionic species during the preparation. The catalytic activities of each zeolite were evaluated, based on the degree of darkening for reaction mixtures containing catechol, glycine and glucose as model humic precursors. The catalytic activities of Fe-Z-1 and Fe-Z-10 were higher than that for an untreated zeolite, and increased with the amount of Fe in the zeolite.


Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1453 ◽  
Author(s):  
Yun Liu ◽  
Yuanhong Xie ◽  
Mingjin Dai ◽  
Qingjiao Gong ◽  
Zhi Dang

A novel photo-Fenton catalyst named Ag/AgCl/MIL-101(Fe) was synthesized by the method of precipitation and photo reduction and characterized by X-ray diffraction patterns (XRD), Brunauer-Emmett-Teller (BET) measurements, Fourier transform infrared spectra (FTIR), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), X-ray photoelectron spectroscopy (XPS) and UV-vis diffuse reflectance spectra. Moreover, the catalytic activity of the synthesized catalyst was tested using methylene blue (MB) as the target pollutant. The obtained results illustrated that the plasmonic material Ag/AgCl was successfully loaded on MIL-101(Fe) and the obtained catalyst exhibited an excellent catalytic activity under visible light at the neutral pH. According to the analyses of Plackett-Burman and Box-Behnken design, the optimum conditions for MB degradation were obtained. Under these conditions, the MB decolorization and mineralization efficiencies could reach to 99.75% and 65.43%, respectively. The recycling experiments also showed that the as-prepared catalyst displayed good reusability. In addition, the possible reaction mechanisms for the heterogeneous photo-Fenton system catalyzed by Ag/AgCl/MIL-101(Fe) were derived. The synthesized catalyst provides a promising approach to degrade organic pollutants in waste water.


2019 ◽  
Vol 10 ◽  
pp. 9-21 ◽  
Author(s):  
Florian Dumitrache ◽  
Iuliana P Morjan ◽  
Elena Dutu ◽  
Ion Morjan ◽  
Claudiu Teodor Fleaca ◽  
...  

Zn/F co-doped SnO2 nanoparticles with a mean diameter of less than 15 nm and a narrow size distribution were synthesized by a one-step laser pyrolysis technique using a reactive mixture containing tetramethyltin (SnMe4) and diethylzinc (ZnEt2) vapors, diluted Ar, O2 and SF6. Their structural, morphological, optical and electrical properties are reported in this work. The X-ray diffraction (XRD) analysis shows that the nanoparticles possess a tetragonal SnO2 crystalline structure. The main diffraction patterns of stannous fluoride (SnF2) were also identified and a reduction in intensity with increasing Zn percentage was evidenced. For the elemental composition estimation, energy dispersion X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) measurements were performed. In general, both analyses showed that the Zn percentage increases with increasing ZnEt2 flow, accompanied at the same time by a decrease in the amount of F in the nanopowders when the same SF6 flow was employed. The Raman spectra of the nanoparticles show the influence of both Zn and F content and crystallite size. The fluorine presence is due to the catalytic partial decomposition of the SF6 laser energy transfer agent. In direct correlation with the increase in the Zn doping level, the bandgap of co-doped nanoparticles shifts to lower energy (from 3.55 to 2.88 eV for the highest Zn dopant concentration).


2020 ◽  
Vol 105 (6) ◽  
pp. 833-847
Author(s):  
Florence T. Ling ◽  
Jeffrey E. Post ◽  
Peter J. Heaney ◽  
Cara M. Santelli ◽  
Eugene S. Ilton ◽  
...  

Abstract With a focus on a large set of natural birnessites collected from terrestrial, freshwater systems, we applied and compared the capabilities of X-ray diffraction (XRD), extended X-ray absorption fine structure (EXAFS), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) to characterize crystal structure and chemistry. Using XRD, we successfully identified 3 of the 11 natural birnessite samples as hexagonal ranciéite-like phases, but the remaining samples yielded less interpretable “3-line” diffraction patterns with broad, asymmetrical peaks at d-spacings of ~7.2, ~2.4, and ~1.4 Å. EXAFS analysis suggested that many of these samples had characteristics of both triclinic and hexagonal birnessite. However, application of EXAFS to the ranciéite-like phases yielded unreasonably high concentrations of triclinic birnessite as an intergrowth, calling into question the use of synthetic hexagonal H-birnessite as an appropriate standard in the linear combination fitting of EXAFS data for natural birnessites. FTIR spectroscopy of the “3-line” birnessite samples successfully distinguished triclinic and hexagonal constituents, and analyses of peak positions suggested that natural birnessites occur as a full spectrum of triclinic and hexagonal intergrowths. XPS analysis of these samples revealed that higher Mn3+ concentrations relative to Mn2+ and Mn4+ are correlated to increased proportions of triclinic birnessite.


2011 ◽  
Vol 284-286 ◽  
pp. 2102-2105 ◽  
Author(s):  
Jin Zhou ◽  
Wen Li ◽  
Shu Ping Zhuo

Several microporous carbons were prepared by a two-step method using zeolite HY as a template, and were used as CO2 adsorbents. X-ray diffraction patterns present that the structure regularity of the zeolite has been well-replicated by the templated carbons. X-ray photoelectron spectroscopy confirms that the prepared carbons possess abundant nitrogen-containing groups due to the carbon deposition of acetonitrile. The prepared carbons show high CO2 adsorption capacity due to its very high microporous surface area and abundant basic nitrogen-containing groups.


2016 ◽  
Vol 87 (4) ◽  
pp. 460-473
Author(s):  
Jianfeng Zhou ◽  
Dandan Zheng ◽  
Fengxiu Zhang ◽  
Guangxian Zhang

In this study, –NH2 groups were introduced to a poly(ethylene terephthalate) (PET) fabric to make the fabric hydrophilic and, then, soybean protein was bonded on the surface of the modified PET fabric to obtain a soybean protein/PET composite fabric. The –NH2 groups allowed the soybean protein to be firmly bonded on the surface of the modified PET fabric. Scanning electron microscopy images showed that the surface of each modified PET fiber had a small number of grooves and that there was a thin film on each soybean protein/PET fiber. Attenuated total reflectance Fourier transform infrared spectra demonstrated that the nitrated and reduced PET fibers were introduced –NH2 groups and that there were –CO–NH– groups on the surface of soybean protein/PET fibers. X-ray photoelectron spectroscopy analyses showed that there was a nitrogen element on the modified PET fibers. The X-ray diffraction patterns suggested that the crystal structures of the modified fibers did not change significantly during the modification processes. The thermogravimetry results showed that the thermal stability of soybean protein/PET fiber kept well. The wearability tests indicated that the breaking strength and elasticity of the original fabric were well retained by the modified fabrics. The soybean protein/PET fabric had good levels of hydrophilicity and softness when the binding rate was below 3.0%.


2006 ◽  
Vol 6 (1) ◽  
pp. 146-150 ◽  
Author(s):  
Colin C. Baker ◽  
Abdullah Ceylan ◽  
S. Ismat Shah

Aluminum Nitride (AlN) nanoparticles were synthesized using a Reactive Gas Condensation (RGC) technique in which a mixture of ammonia (NH3) and nitrogen (N2) gases were used for the nitridation of aluminum. NH3 served as the reactive gas, while N2 served as both a carrier gas and the inert source for particle condensation. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses revealed that at reactive gas compositions greater than 10% NH3 in N2, samples were composed entirely of hexagonal AlN nanoparticles. Electron diffraction patterns showed single crystal hexagonal AlN structure. The particle size was controlled by varying the pressure of the gas mixture. AlN nanoparticles were dispersed in a liquid matrix to enhance thermal conductivity. Results showed that a minimal addition of AlN increased the thermal conductivity of hydrocarbon pump oil by approximately 27%. The thermal conductivity became constant after reaching a maximum above 0.01 wt% AlN. Temporal stability of AlN was studied by XRD. Samples exposed to air for extended periods of time and analyzed by XRD show no degradation of crystalline AlN nanoparticles.


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