Effect of electron beam on the crystal structure of nanoscale Al particles

E-beam irradiation is one of the favorite methods of recent years and it can deliver the irradiation dose in just a few seconds to form nanoparticles. It is possible to obtain nanoparticles with different properties by changing the experimental conditions, as well as radiolytic reduction process can be adjusted through accelerators, it is possible to obtain oxides and hydroxides of metal nanoparticles. This paper reports the investigation of high-energy electron beams (EBs) on the crystal structure of 40–60 nm nanoscale Al particles. The crystal structure of the samples was calculated using the Rietveld method in the FullProf program. Structure analysis of three different irradiated ([Formula: see text], [Formula: see text], [Formula: see text]) Al samples and nonirradiated Al samples was performed by XRD. Occurring energy during the process of linear electron acceleration was around [Formula: see text][Formula: see text]2–3 MeV. All samples were irradiated at room temperature. In addition to STP, temperature changes can be observed when the particles are exposed to high energy for a long time. At STP, nanoscale Al particles combine with the oxygen of the air and form Al2O3. Also, X-ray diffraction study showed that the instability does not only belong to Al particles but also to Al2O3 in view of the fact that precarious Al(OH)3 crystal structures were observed. Thus, radiation dependence of lattice parameters was obtained, the mechanism of change of lattice parameters was determined due to radiation.

Synthesis and NMR study of trimethylphosphine gold(i)-appended calix[8]arenes as precursors of gold nanoparticles

In this paper, the synthesis of gold(i)-calix[8]arene complexes from benzyloxycalix[8]arene is reported as well as their radiolytic reduction leading to gold nanoparticles.

Gold(i)–silver(i)-calix[8]arene complexes, precursors of bimetallic alloyed Au–Ag nanoparticles

We report the synthesis of new bimetallic gold(i)–silver(i) calix[8]arene complexes and their radiolytic reduction leading to small Au–Ag alloyed nanoparticles.

Speciation of technetium in carbonate media under helium ions and γ radiation

Technetium carbonates complexes produced by chemical, electrochemical and radiolytic methods have been studied by UV-Visible, X-ray Absorption Fine Structure (XAFS) and Density Functional Theory methods. The (NH4)2TcCl6 salt was dissolved in 2 M KHCO3. The resulting purple solution was analyzed by XAFS and UV-Visible spectroscopy. The UV-Visible spectra exhibits a band centered at 515 nm. The XAFS results were consistent with the presence of polymeric species containing the [Tc2(μ−O)2]4+ core coordinated to carbonate ligand. Concerning the electrochemical methods, the pertechnetate anion was electrochemically reduced in concentrated carbonate solution [(CO32−)=5 M and (HCO3−)=0.5 M]. For the radiolytic reduction, the speciation of Tc under Helium ions particle beam and γ radiation was examined by UV-Visible and XAFS spectroscopy in high concentrated carbonate media. In concentrated carbonate solutions, pertechnetate as Tc(VII), was not reduced under irradiation due to the formation of carbonate radical which is a strong oxidant. Then, the solution proposed was the addition of formate to the solution which can scavenge hydroxyl radical 10 times faster than carbonate and prevent re-oxidation of reduced technetium. The XANES and EXAFS spectroscopies, approved by theoretical methods, revealed that the final product of the radiolytic reduction of pertechnetate is in the +IV oxidation state. The final structure of the reduced product by He2+ radiolysis was the same as electrochemical reduction. From this complex determination and evolution vs. the dose, this study is reporting the solubility of the Tc(IV) complex.

Bimetallic Pd96Fe4 nanodendrites embedded in graphitic carbon nanosheets as highly efficient anode electrocatalysts

Bimetallic Pd–Fe nanoalloys with tunable composition immobilized on graphitic carbon by one-pot radiolytic reduction show high electrocatalytic activity for alcohol oxidation.