Formation of Droplets during Annealing of Bi2O3 Nanopowder Obtained by Pulsed Electron Beam Evaporation in Vacuum

Author(s):  
S. Yu. Sokovnin ◽  
V. G. Il’ves
2013 ◽  
Vol 8 (7-8) ◽  
pp. 466-481 ◽  
Author(s):  
S. Yu. Sokovnin ◽  
V. G. Il’ves ◽  
A. I. Surdo ◽  
I. I. Mil’man ◽  
M. I. Vlasov

2021 ◽  
Vol 2064 (1) ◽  
pp. 012106
Author(s):  
V G Ilves ◽  
S Y Sokovnin ◽  
M A Uimin

Abstract Various bismuth containing compounds are promising in many applications, including for creating photocatalysts based on them using a visible range of light. However, strong polymorphism (9 polymophic phases of Bi2O3), thermal instability and changes in the properties of bismuth oxide during long-term storage significantly complicate work with it. One way to increase stability and improve photocatalytic properties is by doping Bi2O3 with various metals. Ag doped Bi2O3 nanoparticles (NPs) are typically produced using chemical techniques often associated with the presence of toxic chemicals. The present paper used an environmentally friendly method of producing NPs using the method of pulsed electron beam evaporation in vacuum. The evaporation target was obtained by solid phase synthesis in an electric furnace on air using silver nitrate additives (1 and 5 wt.%). Textural, thermal and magnetic properties of the obtained NPs have been studied. Was found that the Ag-Bi2O3 NPs have a specific surface area (SSA) of 23.7 m2/g, which was almost 2 times bigger than the SSA of the pure Bi2O3 (13.2 m2/g) obtained previously. The thermal stability of the Ag-doped Bi2O3 samples was maintained to the temperature 350°C. While further heating on air took place the phase transition β → α


Author(s):  
С.Ю. Соковнин ◽  
В.Г. Ильвес

Using a method of pulsed electron beam evaporation in vacuum was produced the mesoporous multiphase amorphous and crystal nanopowder of Bi2O3 with a specific surface area up to 23 sq.m/g. Influence of thermal annealing of powder (200-300 0C) in air is investigated. The formation of droplets with a size of 2-5 nm was found on the surface of all large nanoparticles that make up the framework 3D nanopowder agglomerates due to extrusion of liquid bismuth from the volume during cooling.


2021 ◽  
Vol 2064 (1) ◽  
pp. 012087
Author(s):  
A Svetlova ◽  
S Yu Sokovnin ◽  
V G Il’ves

Abstract Nanopowders doped with silver were produced by the method of pulsed electron beam evaporation. The pore sizes of the nanoparticles were 25-32 nm. Evaluation of photocatalytic and cytotoxic properties on cells was carried out. The prospects of using multimodal nanopowders as a photocatalytic agent, as well as for use in medicine, have been shown.


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