Synthesis of Platinum Nanoparticles from K2PtCl4 Solution Using Bacterial Cellulose Matrix

Platinum (Pt) nanoparticles have been synthesized from a precursor solution of potassium tetrachloroplatinate (K2PtCl4) using a matrix of bacterial cellulose (BC). The formation of Pt nanoparticles occurs at the surface and the inside of the BC membrane by reducing the precursor solution with a hydrogen gas reductant. The Pt nanoparticles obtained from the variations of precursor concentration, between 3 mM and 30 mM, and the formation of Pt nanoparticles have been studied using X-ray diffraction (XRD), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), and thermogravimetry analysis (TGA). Based on X-ray diffraction patterns, Pt particles have sizes between 6.3 nm and 9.3 nm, and the Pt particle size increases with an increase in precursor concentration. The morphology of the Pt nanoparticles was observed by SEM-EDS and the content of Pt particles inside the membrane is higher than that on the surface of BC membranes. This analysis corresponds to the TGA analysis, but the TGA analysis is more representative in how it describes the content of Pt particles in the BC membrane.

Download Full-text

Nitrogen, Phosphorus and Sulfur Co-Doped Pyrolyzed Bacterial Cellulose Nanofibers for Supercapacitors

Nanomaterials ◽

10.3390/nano10101912 ◽

2020 ◽

Vol 10 (10) ◽

pp. 1912

Author(s):

Zheng Li ◽

Yaogang Wang ◽

Wen Xia ◽

Jixian Gong ◽

Shiru Jia ◽

...

Keyword(s):

Bacterial Cellulose ◽

High Performance ◽

Electrode Materials ◽

Cellulose Nanofibers ◽

Electrochemical Performances ◽

X Ray Diffraction ◽

X Ray ◽

Diffraction Patterns ◽

Nitrogen Phosphorus ◽

Co Doped

Heteroatom doping is an effective way to raise the electrochemical properties of carbon materials. In this paper, a novel electrode material including nitrogen, phosphorus, and sulfur co-doped pyrolyzed bacterial cellulose (N/P/S-PBC) nanofibers was produced. The morphologies, structure characteristics and electrochemical performances of the materials were investigated by Scanning electron microscopy, Fourier transform infrared spectra, X-ray diffraction patterns, X-ray photoelectronic spectroscopy, N2 sorption analysis and electrochemical measurements. When 3.9 atom% of nitrogen, 1.22 atom% of phosphorus and 0.6 atom% of sulfur co-doped into PBC, the specific capacitance of N/P/S-PBC at 1.0 A/g was 255 F/g and the N/P/S-PBC supercapacitors’ energy density at 1 A/g was 8.48 Wh/kg with a power density of 489.45 W/kg, which were better than those of the N/P-PBC and N/S-PBC supercapacitors. This material may be a very good candidate as the promising electrode materials for high-performance supercapacitors.

Download Full-text

Development of an in situ synchrotron X-ray total scattering setup under pressurized hydrogen gas

Journal of Applied Crystallography ◽

10.1107/s1600576718005101 ◽

2018 ◽

Vol 51 (3) ◽

pp. 796-801 ◽

Cited By ~ 3

Author(s):

Kouji Sakaki ◽

Hyunjeong Kim ◽

Akihiko Machida ◽

Tetsu Watanuki ◽

Yoshinori Katayama ◽

...

Keyword(s):

Pair Distribution Function ◽

Hydrogen Gas ◽

Ex Situ ◽

Sample Holder ◽

Hydrogen Storage Materials ◽

X Ray Diffraction ◽

Total Scattering ◽

X Ray ◽

Diffraction Patterns

This article describes the development of an in situ gas-loading sample holder for synchrotron X-ray total scattering experiments, particularly for hydrogen storage materials, designed to collect diffraction and pair distribution function (PDF) data under pressurized hydrogen gas. A polyimide capillary with a diameter and thickness of 1.4 and 0.06 mm, respectively, connected with commercially available Swagelok fittings was used as an in situ sample holder. Leakage tests confirmed that this sample holder allows 3 MPa of hydrogen gas pressure and 393 K to be achieved without leakage. Using the developed in situ sample holder, significant background and Bragg peaks from the sample holder were not observed in the X-ray diffraction patterns and their signal-to-noise ratios were sufficiently good. The PDF patterns showed sharp peaks in the r range up to 100 Å. The results of Rietveld and PDF refinements of Ni are consistent with those obtained using a polyimide capillary (1.0 mm diameter and 0.04 mm thickness) that has been used for ex situ experiments. In addition, in situ synchrotron X-ray total scattering experiments under pressurized hydrogen gas up to 1 MPa were successfully demonstrated for LaNi4.6Cu.

Download Full-text

A Quantitative Picture of the Fringed Micellar Model of Cellulose

Textile Research Journal ◽

10.1177/004051757104100802 ◽

1971 ◽

Vol 41 (8) ◽

pp. 647-653 ◽

Cited By ~ 36

Author(s):

A. M. Scallan

Keyword(s):

Acid Hydrolysis ◽

Bacterial Cellulose ◽

Deuterium Oxide ◽

Tire Cord ◽

X Ray Diffraction ◽

Wood Cellulose ◽

X Ray ◽

Diffraction Patterns ◽

Recent Interpretation

Quantitative diagrams of the fringed micellar model have been produced for tire cord, Fortisan, wood cellulose, cotton, ramie and bacterial cellulose, based on the results of the reactivities of these celluloses towards deuterium oxide and acid hydrolysis. The hypothesis has been used that rapid acid hydrolysis occurs in the truly amorphous zones, whereas deuteration occurs not only in these zones but also on the surfaces of the crystallites. It is from this hypothesis that calculations of crystallinity, crystallite width, and crystallite length have been made. The calculated fractional crystallinities of native celluloses are, therefore, in the range of 0.89-0.96, while those of regenerated celluloses range from 0.65 to 0.85. These crystallinities are higher than previously accepted values and are more in keeping with the most recent interpretation of x-ray diffraction patterns. The values of calculated crystallite width were about 17Å for the regenerated celluloses and 32Å for native celluloses. The latter value is close to that currently proposed by electron microscopists. Crystallite lengths were calculated from the levelling-off DP found on acid hydrolysis. The various methods of measuring crystallinity are discussed in terms of the model, as are microfibrils, crystallites, and paracrystalline cellulose.

Download Full-text

Structural and In Situ X-ray Diffraction Study of Hydrogenation of CaxMg1−xNi2 (0 ≤ x ≤ 1)

Crystals ◽

10.3390/cryst12010047 ◽

2021 ◽

Vol 12 (1) ◽

pp. 47

Author(s):

Zia Ur Rehman ◽

Mohsan Nawaz ◽

Hameed Ullah ◽

Pervaiz Ahmad ◽

Mayeen Uddin Khandaker ◽

...

Keyword(s):

Electron Microscopy ◽

Powder Diffraction ◽

Gas Flow ◽

Hydrogen Gas ◽

Laves Phase ◽

X Ray Diffraction ◽

X Ray ◽

Phase Type ◽

Diffraction Patterns

In the quasi-binary system CaNi2-MgNi2 solid-solutions CaxMg1−xNi2 (0 ≤ x ≤ 1) were prepared from the elements. They crystallize in the hexagonal Laves phase type (MgNi2, C36) for x ≤ 0.33 (P63/mmc, a = 482.51(7) pm, c = 1582.1(3) pm for x = 0, a = 482.59 (3), c = 1583.1(1) for x = 0.33) and in the cubic Laves phase type (MgCu2, C15) for 0.33 < x (Fd−3m, a = 697.12(3) pm for x = 0.5, a = 705.11(2) pm for x = 0.67, a = 724.80(2) pm for x = 1). After hydrogenation in an autoclave the X-ray diffraction patterns changed completely. Reflections assigned to CaNiH3, and Ni and Rietveld refinement confirmed this. The hydrogenation properties of CaxMg1−xNi2 (0 ≤ x ≤ 1) compounds were also studied in situ by X-ray powder diffraction. In situ X-ray powder diffraction of CaxMg1−xNi2 (0 ≤ x ≤ 1) compounds under 0.3 MPa hydrogen gas flow (15 sccm), data collected on a Rigaku SmartLab diffractometer in an Anton Paar XRK 900 Reactor Chamber using Cu-Kα1 radiation. Scanning electron microscopy and EDX spectroscopy confirmed the entitled materials and elemental composition, respectively. From the Transmission electron microscopy and Selected area electron diffraction concluded that the CaxMg1−xNi2 (0 ≤ x ≤ 1) compounds were crystalline.

Download Full-text

Structural Transition of Trimethylamine Hydrate by Methane or Hydrogen Inclusion

10.5194/egusphere-egu2020-3806 ◽

2020 ◽

Author(s):

Minjun Cha

Keyword(s):

Structural Transition ◽

Guest Molecule ◽

Clathrate Hydrate ◽

Hydrogen Gas ◽

Time Dependent ◽

X Ray Diffraction ◽

Guest Molecules ◽

X Ray ◽

Inclusion Process ◽

Diffraction Patterns

Recently, several alkylamine hydrates have been studied in an effort to reveal the structural transitions from semi- to &#8216;canonical&#8217; clathrate hydrate in the presence of secondary guest molecules. Trimethylamine (TMA) is known to form the semi-clathrate hydrate, and it has been reported that the structural transition of the TMA semi-clathrate hydrate may not occur in the presence of hydrogen gas as a secondary guest molecule. This paper reports the structural transition of trimethylamine(TMA) hydrate induced by the type of guest molecules. Powder X-ray diffraction patterns of (TMA + H2) hydrates show the formation of hexagoanl P6/mmm hydrate, but those of (TMA + CH4) hydrates indicate the formation of cubic Fd3m hydrate. Without gaseous guest molecule, the crystal structure of pure TMA hydrate is identified as hexagonal P6/mmm. Therefore, inclusion of gaseous methane in TMA hydrate can induce the structural transition from hexagonal to cubic hydrate or the formation of metastable cubic hydrate. To clearly reveal this possibility, we also check the time-dependent structural patterns of binary (TMA + CH4) hydrates from 1 to 14 days, and the results show that the structural transition of TMA hydrate from hexagonal P6/mmm to cubic Fd3m hydrate structure can occur during the methane inclusion process.

Download Full-text

Morphology Manipulation and Related Properties of High Crystalline Bi2S3 Nanorods by Reflux Approach

Journal of Nanoscience and Technology ◽

10.30799/jnst.159.18040516 ◽

2018 ◽

Vol 4 (5) ◽

pp. 524-526

Author(s):

J. Arumugam ◽

A. Dhayal Raj ◽

A. Albert Irudayaraj

Keyword(s):

High Resolution ◽

Critical Role ◽

Precursor Concentration ◽

X Ray Diffraction ◽

X Ray ◽

Increase With Increase ◽

Crystallite Sizes ◽

Ftir Spectrometer ◽

Diffraction Patterns ◽

Transmission Microscope

One dimensional Bi2S3 nanorods have been successfully synthesized by a very simple reflux method with different precursor concentration for 2 hours at 180 �C. The as-synthesized Bi2S3 powders were characterized by X-ray diffraction (XRD), high resolution scanning electron microscope (HRSEM), high resolution transmission microscope (HRTEM), UV-Vis spectrometer, Fourier transform infrared (FTIR) spectrometer. X-ray diffraction (XRD) results show that the resulting nanocrystals have an orthorhombic structure. X-ray diffraction patterns indicate a polycrystalline nature and the crystallite sizes seem increase with increase in the concentration. The HRSEM and HRTEM images reveal that the diameter of the nanorods increase with increasing concentration of the precursor. Morphological analysis reveals that the as-prepared Bi2S3 nanorods can be tuned to morphology by varying precursor concentration from 0.01 M to 0.001 M. The bismuth nitrate, which is known to be a linear polymer, plays a critical role as a precursor and a template for the growth of uniform Bi2S3 nanorods. Bi2S3 nanorods are good absorbents of solar radiation and hence can be used in solar cells.

Download Full-text

Evaluation of Freezing Methods by Low Temperature X-Ray Diffraction

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100079176 ◽

1977 ◽

Vol 35 ◽

pp. 330-333

Author(s):

T. Gulik-Krzywicki ◽

M.J. Costello

Keyword(s):

Biological Materials ◽

Molecular Organization ◽

X Ray Diffraction ◽

Glass Capillary ◽

X Ray ◽

Rate Dependent ◽

Before And After ◽

Freeze Etching ◽

Diffraction Patterns ◽

Set Up

Freeze-etching electron microscopy is currently one of the best methods for studying molecular organization of biological materials. Its application, however, is still limited by our imprecise knowledge about the perturbations of the original organization which may occur during quenching and fracturing of the samples and during the replication of fractured surfaces. Although it is well known that the preservation of the molecular organization of biological materials is critically dependent on the rate of freezing of the samples, little information is presently available concerning the nature and the extent of freezing-rate dependent perturbations of the original organizations. In order to obtain this information, we have developed a method based on the comparison of x-ray diffraction patterns of samples before and after freezing, prior to fracturing and replication.Our experimental set-up is shown in Fig. 1. The sample to be quenched is placed on its holder which is then mounted on a small metal holder (O) fixed on a glass capillary (p), whose position is controlled by a micromanipulator.

Download Full-text

Examination of Rabbit Fc Crystals

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100100445 ◽

1968 ◽

Vol 26 ◽

pp. 140-141

Author(s):

J. P. Robinson ◽

P. G. Lenhert

Keyword(s):

Molecular Weight ◽

Flat Plate ◽

Phosphate Buffer ◽

Asymmetric Unit ◽

X Ray Diffraction ◽

X Ray ◽

Neutral Ph ◽

Small Crystals ◽

Carbon Coated ◽

Diffraction Patterns

Crystallographic studies of rabbit Fc using X-ray diffraction patterns were recently reported. The unit cell constants were reported to be a = 69. 2 A°, b = 73. 1 A°, c = 60. 6 A°, B = 104° 30', space group P21, monoclinic, volume of asymmetric unit V = 148, 000 A°3. The molecular weight of the fragment was determined to be 55, 000 ± 2000 which is in agreement with earlier determinations by other methods.Fc crystals were formed in water or dilute phosphate buffer at neutral pH. The resulting crystal was a flat plate as previously described. Preparations of small crystals were negatively stained by mixing the suspension with equal volumes of 2% silicotungstate at neutral pH. A drop of the mixture was placed on a carbon coated grid and allowed to stand for a few minutes. The excess liquid was removed and the grid was immediately put in the microscope.

Download Full-text

Control of the phase composition of advanced calcium phosphates using an x-ray diffractometer with a curved position-sensitive detector

Industrial laboratory Diagnostics of materials ◽

10.26896/1028-6861-2020-86-6-29-35 ◽

2020 ◽

Vol 86 (6) ◽

pp. 29-35

Author(s):

V. P. Sirotinkin ◽

O. V. Baranov ◽

A. Yu. Fedotov ◽

S. M. Barinov

Keyword(s):

Phase Composition ◽

Calcium Phosphates ◽

Position Sensitive Detector ◽

Sensitive Detector ◽

X Ray Diffraction ◽

X Ray ◽

Impurity Phases ◽

Position Sensitive ◽

Diffraction Peaks ◽

Diffraction Patterns

The results of studying the phase composition of advanced calcium phosphates Ca10(PO4)6(OH)2, β-Ca3(PO4)2, α-Ca3(PO4)2, CaHPO4 · 2H2O, Ca8(HPO4)2(PO4)4 · 5H2O using an x-ray diffractometer with a curved position-sensitive detector are presented. Optimal experimental conditions (angular positions of the x-ray tube and detector, size of the slits, exposure time) were determined with allowance for possible formation of the impurity phases during synthesis. The construction features of diffractometers with a position-sensitive detector affecting the profile characteristics of x-ray diffraction peaks are considered. The composition for calibration of the diffractometer (a mixture of sodium acetate and yttrium oxide) was determined. Theoretical x-ray diffraction patterns for corresponding calcium phosphates are constructed on the basis of the literature data. These x-ray diffraction patterns were used to determine the phase composition of the advanced calcium phosphates. The features of advanced calcium phosphates, which should be taken into account during the phase analysis, are indicated. The powder of high-temperature form of tricalcium phosphate strongly adsorbs water from the environment. A strong texture is observed on the x-ray diffraction spectra of dicalcium phosphate dihydrate. A rather specific x-ray diffraction pattern of octacalcium phosphate pentahydrate revealed the only one strong peak at small angles. In all cases, significant deviations are observed for the recorded angular positions and relative intensity of the diffraction peaks. The results of the study of experimentally obtained mixtures of calcium phosphate are presented. It is shown that the graphic comparison of experimental x-ray diffraction spectra and pre-recorded spectra of the reference calcium phosphates and possible impurity phases is the most effective method. In this case, there is no need for calibration. When using this method, the total time for analysis of one sample is no more than 10 min.

Download Full-text

Infrared spectroscopic study of the YPO4-YCrO4 system

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19852139 ◽

1985 ◽

Vol 50 (10) ◽

pp. 2139-2145

Author(s):

Alexander Muck ◽

Eva Šantavá ◽

Bohumil Hájek

Keyword(s):

Spectroscopic Study ◽

Infrared Spectra ◽

Point Of View ◽

Mixed Crystals ◽

Crystal Symmetry ◽

Infrared Spectroscopic Study ◽

X Ray Diffraction ◽

X Ray ◽

Infrared Spectroscopic ◽

Diffraction Patterns

The infrared spectra and powder X-ray diffraction patterns of polycrystalline YPO4-YCrO4 samples are studied from the point of view of their crystal symmetry. Mixed crystals of the D4h19 symmetry are formed over the region of 0-30 mol.% YPO4 in YCrO4. The Td → D2d → D2 or C2v(GS eff) correlation is appropriate for both PO43- and CrO43- anions.

Download Full-text