scholarly journals Synthesis and characterization of ternary Pt-alloy nano particles for hydrogen fuel cell application

2020 ◽  
Vol 12 (1) ◽  
pp. 419-425
Author(s):  
Alhassan Kabiru Usman ◽  
Kamal Danazumi
Keyword(s):  
Electron Microscope ◽  
Average Particle Size ◽  
Carbon Support ◽  
Peak Position ◽  
Reduction Reaction ◽  
Nano Particles ◽  
Alloy Formation ◽  
Average Particle ◽  
Hydrogen Fuel Cell ◽  
Tem Analysis

A novel ternary PtM2 nano structures was prepared using simple salvothermal process. The alloy formation has been ascertained using different characterizations techniques such as X-ray diffraction, Tunneling electron microscope TEM, Scanning electron microscope SEM, EDX. The XRD pattern reveals that, the peak position was shifted to higher 2𝜃 angle specifying the presence of Co and Ni into the lattice to form an ordered L10 phase with a reduced Pt-Pt distance. The thickness of the alloy was found to be ~4.3nm and interplaner distance of ~0.23nm which correlate with TEM analysis with an average particle size ~20nm and distribution of the catalyst on carbon support was also investigated by TEM images. SEM was used to obtain the surface morphology of the synthesized catalyst as well the amount of metallic loaded from EDX. Key words; Platinum, Cobalt, Nickel on Carbon Support (PCN/C), Platinum, Cobalt and Nickel for 8 hour (PCN-8h), Commercial Platinum on Carbon Support (Pt/C), Oxidation Reduction Reaction (ORR), PEMFC, SEM, EDX, TEM, XRD.  

scholarly journals Biosynthesis of Gold Nanoparticles by Essential Oil of Diplotaxis Acris Characterization and Antimicrobial Activities

2021 ◽  
Vol 37 (2) ◽  
pp. 405-412
Author(s):  
Mohamed Habib Oueslati ◽  
Lotfi Ben Tahar ◽  
A. Khuzaim Alzahrani ◽  
Jamith Basha ◽  
Omar H. Abd Elkader
Keyword(s):  
Essential Oil ◽  
Average Particle Size ◽  
Antimicrobial Activities ◽  
Nano Particles ◽  
Average Particle ◽  
Tem Analysis ◽  
Stabilizing Agents ◽  
E Coli ◽  
Ft Ir ◽  
Plausible Scheme

The present work reports a green biosynthesis of gold nano particles (EO-AuNPs) using an essential oil (EO) as a reducing agent of the Au(III) in HAuCl4. The EO was extracted by hydro-distillation from Diplotaxis acris flowers. A total of 16 compounds were detected from the EO oil by using GC–MS and 5-methylsulfanylpentanenitrile was identified as the major component (73.60 %). The biosynthesized EO-AuNPs were characterized performing UV–Vis, IR,XRD and TEM analyses.The UV-Vis revealed the typical features of surface plasmon resonance (SPR) of AuNPs at ~526 nm. The FT-IR spectrum of the biosynthesized nano particles exhibited the features of the nitrile (-C≡N) functional group indicating that the -C≡N-bearing EO components are likely acting as reducing and stabilizing agents for the formation of EO-AuNPs. The plausible scheme of EO-AuNPsformation was proposed.The TEM analysis showed that the EO- AuNPs were almost spherical in shape with an average particle size of 12.7 nm. In addition, the antimicrobial activity was carried out by diffusion of agar wells method. The results proved that the EO-AuNPs displayed a potential antimicrobial against gram negative strains, with a maximum zone of inhibition of 16 mm for E. coli at a concentration of 100 µg / ml.

scholarly journals Synthesis of Gold Nanoparticles by Using Green Machinery: Characterization and In Vitro Toxicity

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 808
Author(s):  
Ahmed Al Saqr ◽  
El-Sayed Khafagy ◽  
Ahmed Alalaiwe ◽  
Mohammed F. Aldawsari ◽  
Saad M. Alshahrani ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Average Particle Size ◽  
In Vitro Cytotoxicity ◽  
In Vitro Toxicity ◽  
Cervical Cancer Cell Line ◽  
Average Particle ◽  
Anticancer Activities ◽  
Tem Analysis ◽  
Benincasa Hispida

Green synthesis of gold nanoparticles (GNPs) with plant extracts has gained considerable interest in the field of biomedicine. Recently, the bioreduction nature of herbal extracts has helped to synthesize spherical GNPs of different potential from gold salt. In this study, a fast ecofriendly method was adopted for the synthesis of GNPs using fresh peel (aqueous) extracts of Benincasa hispida, which acted as reducing and stabilizing agents. The biosynthesized GNPs were characterized by UV–VIS and Fourier transform infrared spectroscopy, transmission electron microscopy (TEM), and dynamic light scattering. In addition, the in vitro antibacterial and anticancer activities of synthesized GNPs were investigated. The formation of gold nanoparticles was confirmed by the existence of a sharp absorption peak at 520 nm, corresponding to the surface plasmon resonance (SPR) band of the GNPs. TEM analysis revealed that the prepared GNPs were spherical in shape and had an average particle size of 22.18 ± 2 nm. Most importantly, the synthesized GNPs exhibited considerable antibacterial activity against different Gram-positive and Gram-negative bacteria. Furthermore, the biosynthesized GNPs exerted remarkable in vitro cytotoxicity against human cervical cancer cell line, while sparing normal human primary osteoblast cells. Such cytotoxic effect was attributed to the increased production of reactive oxygen species (ROS) that contributed to the damage of HeLa cells. Collectively, peel extracts of B. hispida can be efficiently used for the synthesis of GNPs, which can be adopted as a natural source of antimicrobial and anticancer agent.

scholarly journals Preparation and Electrocatalytic Characteristics Research of Pd/C Catalyst for Direct Ethanol Fuel Cell

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Qiao Xia Li ◽  
Ming Shuang Liu ◽  
Qun Jie Xu ◽  
Hong Min Mao
Keyword(s):  
Fuel Cell ◽  
Average Particle Size ◽  
Active Surface ◽  
Carbon Support ◽  
Catalytic Performance ◽  
Active Surface Area ◽  
Average Particle ◽  
Ethanol Fuel ◽  
Direct Ethanol Fuel Cell ◽  
Electrochemical Active Surface Area

Two kinds of carbon-support 20% Pd/C catalysts for use in direct ethanol fuel cell (DEFC) have been prepared by an impregnation reduction method using NaBH4and NaH2PO2as reductants, respectively, in this study. The catalysts were characterized by XRD and TEM. The results show that the catalysts had been completely reduced, and the catalysts are spherical and homogeneously dispersed on carbon. The electrocatalytic activity of the catalysts was investigated by electrochemical measurements. The results indicate that the catalysts had an average particle size of 3.3 nm and showed the better catalytic performance, when NaBH4was used as the reducing agent. The electrochemical active surface area of Pd/C (NaBH4) was 56.4 m2·g−1. The electrochemical activity of the Pd/C (NaBH4) was much higher than that of Pd/C (NaH2PO2).

scholarly journals Preparation of Polyetherimide Nanoparticles by a Droplet Evaporation-Assisted Thermally Induced Phase-Separation Method

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1548
Author(s):  
Peng Zhu ◽  
Huapeng Zhang ◽  
Hongwei Lu
Keyword(s):  
Particle Size ◽  
Electron Microscope ◽  
Phase Separation ◽  
Average Particle Size ◽  
Particle Diameter ◽  
Droplet Evaporation ◽  
Average Particle ◽  
Thermally Induced Phase Separation ◽  
Thermally Induced ◽  
Pei Nanoparticles

The droplet evaporation effect on the preparation of polyetherimide (PEI) nanoparticles by thermally induced phase separation (TIPS) was studied. PEI nanoparticles were prepared in two routes. In route I, the droplet evaporation process was carried out after TIPS. In route II, the droplet evaporation and TIPS processes were carried out simultaneously. The surface tension and shape parameters of samples were measured via a drop shape analyzer. The Z-average particle diameter of PEI nanoparticles in the PEI/dimethyl sulfoxide solution (DMSO) suspension at different time points was tested by dynamic light scattering, the data from which was used to determine the TIPS time of the PEI/DMSO solution. The natural properties of the products from both routes were studied by optical microscope, scanning electron microscope and transmission electron microscope. The results show that PEI nanoparticles prepared from route II are much smaller and more uniform than that prepared from route I. Circulation flows in the droplet evaporation were indirectly proved to suppress the growth of particles. At 30 °C, PEI solid nanoparticles with 193 nm average particle size, good uniformity, good separation and good roundness were obtained. Route I is less sensitive to temperature than route II. Samples in route I were still the accumulations of micro and nanoparticles until 40 °C instead of 30 °C in route II, although the particle size distribution was not uniform. In addition, a film structure would appear instead of particles when the evaporation temperature exceeds a certain value in both routes. This work will contribute to the preparation of polymer nanoparticles with small and uniform particle size by TIPS process from preformed polymers.

A Study of Nanosize Fe3O4 Deposited on Carbon Matrix

2008 ◽  
Vol 8 (2) ◽  
pp. 591-594 ◽  
Author(s):  
B. Banov ◽  
L. Ljutzkanov ◽  
I. Dimitrov ◽  
A. Trifonova ◽  
H. Vasilchina ◽  
...  
Keyword(s):  
Average Particle Size ◽  
Carbon Matrix ◽  
Reversible Capacity ◽  
Carbon Support ◽  
Test Sample ◽  
Constant Current ◽  
Average Particle ◽  
Scanning Electron Micrographs ◽  
Lithium Secondary Batteries ◽  
Electrochemical Tests

Nanosized crystalline Fe3O4 (with an average particle size of 16 nm) was successfully synthesized on a carbon matrix surface. The prepared sample was heat-treated in the temperature range 300 °C–750 °C to remove residual impurities and to obtain a final product with a 77:23 ratio between magnetite and the carbon support. The sample was subjected to physicochemical and electrochemical tests. The purity of the phase and the particles size was determined by X-ray diffraction analysis and confirmed by field emission scanning electron micrographs. The specific surface area of the sample measured by the B.E.T method was 120 m2 g−1. A series of electrochemical tests including EIS, CV and long-term constant current cycling have been performed. The obtained reversible capacity within 15 cycles was in the range 400–550 mA h · g−1. The electrochemical behavior of the test sample and its possible practical use as an anode material in lithium secondary batteries are discussed.

scholarly journals Photoluminescences properties of lanthanum-silver co-doped ZnO nano particles

2018 ◽  
Vol 4 (4) ◽  
pp. 135-141 ◽  
Author(s):  
V. Porkalai ◽  
B. Sathya ◽  
D. Benny Anburaj ◽  
G Nedunchezhian ◽  
S. Joshua Gnanamuthu ◽  
...  
Keyword(s):  
Zno Nanoparticles ◽  
Zinc Acetate Dihydrate ◽  
Average Particle Size ◽  
Semiconductor Nanoparticles ◽  
Nano Particles ◽  
Average Particle ◽  
Rare Earth Ion ◽  
X Ray ◽  
Doped Zno ◽  
Co Doped

Recently, transition metal (TM) and rare earth ion doped II–VI semiconductor nanoparticles have received much attention because such doping can modify and improve optical properties of II–VI semiconductor nanoparticles by large amount. In this study, undoped, La doped and La+Ag co-doped ZnO nano particles have been successfully synthesized by sol-gel method using the mixture of Zinc acetate dihydrate and ethanol solution. The powders were calcinated at 600 °C for 2 h. The effect of lanthanum and lanthanum-silver incorporation on the structure, morphology, optical and electrical conductivity were examined by X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive X-ray Absorption (EDAX), Fourier transform infrared spectroscopy (FTIR), UV and Photo Luminescence (PL) Characterization. The average particle size of the synthesized ZnO nanoparticles is calculated using the Scherrer formula and is found to be of less than 20 nm. Luminescences properties were found to be enhanced for the La and La+Ag co-doped ZnO nanoparticles.

scholarly journals Effect of Nanosized Colloidal Copper on Cotton Fabric

2010 ◽  
Vol 5 (3) ◽  
pp. 155892501000500 ◽  
Author(s):  
D.P. Chattopadhyay ◽  
B.H. Patel
Keyword(s):  
Particle Size ◽  
Cotton Fabric ◽  
Colloidal Solution ◽  
Chemical Reduction ◽  
Average Particle Size ◽  
Particle Size Analysis ◽  
Nano Particles ◽  
Size Analysis ◽  
Average Particle ◽  
Sem Images

This research deals with the synthesis of nanosized copper as colloidal solution and its application to cotton fabric. Copper nano colloids were prepared by chemical reduction of copper salt using sodium borohydride as reducing agent in presence of tri-sodium citrate. The size and size distribution of the particles were examined by particle size analyzer and the morphology of the synthesized particles was examined by SEM and AFM techniques. X-ray fluorescence spectroscopy detected the presence of copper in the treated fabric. The results of particle size analysis showed that the average particle size varied from 60 nm to 100 nm. The nano copper treated cotton was subjected to soil burial test for the assessment of its resistance towards microbial attack. SEM images of treated fabric indicate copper nano particles are well dispersed on the surface of the specimens. The treatments of nano copper colloidal solution on cotton not only improve its antimicrobial efficiency but also influenced the tensile strength of the fabric sample positively. The treatment was found to enhance the color depth and fastness properties of direct dyed cotton fabric samples.

scholarly journals Preparation of ultrafine iron phosphate micro-powder from phosphate slag

2018 ◽  
Vol 238 ◽  
pp. 02002
Author(s):  
Fangjing Sun ◽  
Yi Zhang ◽  
Jiawei Zhang ◽  
Xixi Yan ◽  
Xiaoyu Liu ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Electron Microscope ◽  
Average Particle Size ◽  
Iron Phosphate ◽  
Average Particle ◽  
X Ray ◽  
Particle Size Analyzer ◽  
Phosphate Slag ◽  
Scanning Electron

In this experiment, ultrafine iron phosphate micro-powder was prepared by hydrothermal method which used phosphate slag as an iron source. The effects of reaction temperature, surfactants type and amount on its particle size were explored. The samples were characterized by using Malvern Laser Particle Size Analyzer (MS2000), X-Ray Diffractometer (XRD), Scanning Electron Microscope (SEM) and Energy Dispersive X-Ray Spectroscopy (EDX).The results showed that at 160 °C, 1 wt%CTAB, monoclinic iron phosphate micro-powder was obtained with an average particle size about 0.4 μm which also has a good dispersion in aqueous solution.

scholarly journals Synthesis of Nanocrystalline Cellulose Stabilized Copper Nanoparticles

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Aminu Musa ◽  
Mansor B. Ahmad ◽  
Mohd Zobir Hussein ◽  
Saiman Mohd Izham ◽  
Kamyar Shameli ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Copper Nanoparticles ◽  
Metal Ion ◽  
Copper Ions ◽  
Chemical Reduction ◽  
Average Particle Size ◽  
Nanocrystalline Cellulose ◽  
Average Particle ◽  
Face Centered Cubic ◽  
X Ray

A chemical reduction method was employed for the synthesis of copper nanoparticles stabilized by nanocrystalline cellulose (NCC) using different concentrations of copper salt in aqueous solution under atmospheric air. CuSO4·5H2O salt and hydrazine were used as metal ion precursor and reducing agent, respectively. Ascorbic acid and aqueous NaOH were also used as an antioxidant and a pH moderator, respectively. The number of CuNPs increased with increasing concentration of the precursor salt. The formation of copper nanoparticles stabilized by NCC (CuNPs@NCC) was investigated by UV-visible spectroscopy (UV-vis), where the surface absorption maximum was observed at 590 nm. X-ray diffraction (XRD) analysis showed that the CuNPs@NCC are of a face-centered cubic structure. Moreover, the morphology of the CuNPs@NCC was investigated using transmission electron microscope (TEM) and field emission scanning electron microscope (FESEM), which showed well-dispersed CuNPs with an average particle size less than 4 nm and the shape of CuNPs was found to be spherical. Energy dispersive X-ray spectroscope (EDS) also confirmed the presence of CuNPs on the NCC. The results demonstrate that the stability of CuNPs decreases with an increasing concentration of the copper ions.

scholarly journals Mechanochemical Preparation of Pd(II) and Pt(II) Composites with Carbonaceous Materials and Their Application in the Suzuki-Miyaura Reaction at Several Energy Inputs

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2951 ◽  
Author(s):  
Mohamed M.A. Soliman ◽  
Andreia F. Peixoto ◽  
Ana P.C. Ribeiro ◽  
Maximilian N. Kopylovich ◽  
Elisabete C.B.A. Alegria ◽  
...  
Keyword(s):  
Phenylboronic Acid ◽  
Average Particle Size ◽  
Conventional Heating ◽  
Average Particle ◽  
Ambient Conditions ◽  
Mechanical Grinding ◽  
Multiwalled Carbon ◽  
Tem Analysis ◽  
Energy Inputs ◽  
Icp Ms

Pd(II) and Pt(II) composites with activated carbon (AC), graphene oxide, and multiwalled carbon nanotubes were prepared by ball milling and used as catalysts for the Suzuki-Miyaura reaction, under several energy inputs (mechanical grinding, conventional heating, and microwave irradiation). The catalytic composites were characterized by ICP-MS, BET, XPS analyses, TEM, and SEM. The average particle size of the prepared composites was estimated to be in the range of 6–30 nm, while the loadings of Pd and Pt did not significantly affect the surface area of the AC support due to the tendency to agglomerate as observed by the TEM analysis. The Pd/AC composites exhibit high mechanochemical catalytic activity in cross-coupling of bromobenzene and phenylboronic acid with molar yields up to 80% with TON and TOF of 222 and 444 h−1, respectively, achieved with Pd(4.7 wt%)-AC catalyst under the liquid assisted grinding for 0.5 h at ambient conditions, using cyclohexene as an additive.

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