Investigation of the Structural Changes and Catalytic Properties of FeNi Nanostructures as a Result of Exposure to Gamma Radiation

Abstract

The paper presents the results of changes in the structural characteristics, and the degree of texturing of FeNi nanostructures close in composition to permalloy compounds as a result of directed modification by gamma radiation with an energy of 1.35 MeV and doses from 100 to 500 kGy. The choices of energy and radiation doses were due to the need to modify the structural properties, which consisted of annealing the point defects that occurred during the synthesis along the entire length of the nanotubes. The initial FeNi nanostructures were polycrystalline nanotubes of anisotropic crystallite orientation, obtained by electrochemical deposition. The study found that exposure to gamma rays led to fewer defects in the structure, and reorientation of crystallites, and at doses above 300 kGy, the presence of one selected texture direction (111) in the structure. During tests of the corrosion resistance of synthesized and modified nanostructures in a PBS solution at various temperatures, it was found that exposure to gamma rays led to a significant decrease in the rate of degradation of nanotubes and an increase in the potential life of up to 20 days. It was established that at the first stage of testing, the degradation of nanostructures is accompanied by the formation of oxide inclusions, which subsequently lead to the formation of pitting corrosion and subsequent partial or complete destruction of the nanostructures. It is shown that gamma radiation is promising not only for targeted modification of nanostructures and increasing resistance to degradation, but also for increasing the rate of catalytic reactions of the PNA-PPD type.

Investigation of the applicability of post-irradiation annealing to reduce the degree of disorder in AlN ceramic to proton irradiation

“…Figure 3a shows the dynamics of changes in macrostresses resulting from distortion and deformation of interplanar spacings. The magnitudes of macrostresses were estimated on the basis of an analysis of the displacement of the three most intense diffraction reflections characterizing a change in the positions of interplanar spacings in the structure of ceramics (2) [53]:…”

The study of the applicability of invar nanostructures for the reduction of p-nitrophenyl compounds

“…have a higher productivity and surface selectivity, and the possibility of phase transformations with the formation of oxide phases in the surface layer can significantly increase the productivity of the catalysts [5][6][7][8]. The presence of a complex phase structure and a large number of grain boundaries for nanostructures serves as additional catalytic centers that make it possible to accelerate the reduction process, without forming agglomerates, which leads to an increase in the operating life [9,10]. In turn, catalytic reduction processes can be accelerated using oxide structures with a rather complicated electronic structure and multiphase nanostructures [11][12][13].…”