Synthesis of Ag-Au nanostructures by galvanic replacement
Students Name: Lapa Anastasiia Viktorivna
Qualification Level: master (ESP)
Speciality: Chemical Technology and Engineering
Institute: Institute of Chemistry and Chemical Technologies
Mode of Study: full
Academic Year: 2022-2023 н.р.
Language of Defence: ukrainian
Abstract: The master’s qualification work consists of an explanatory note with a total volume of 84 pages (including 9 tables, 40 figures, a list of literature from 74 items) and a demonstration part - a presentation (total volume - 21 slides). The object of research is solutions of stabilized silver nanoparticles and Ag-Au bimetallic nanostructures. The master’s qualification work provides an analysis of sources of information on methods of synthesis of bimetallic nanoparticles, their main characteristics and fields of application. It is shown that one of the effective methods of forming bimetals, and in particular Ag-Au nanostructures, is galvanic replacement. By changing the concentration and nature of precursor salt solutions, the temperature and duration of galvanic replacement can be controlled by the composition and morphology of the synthesized nanoparticles A description of experimental research methods, laboratory installations, reagents and analysis methods is given. The work presents the results of experimental research on establishing the regularities of the synthesis of: 1) silver nanoparticles by galvanic replacement of argentum ions with magnesium in sodium polyacrylate solutions in an ultrasound field; 2) synthesis of Ag-Au bimetallic nanoparticles by galvanic replacement of the obtained silver nanoparticles and HAuCl4 solutions. The results of the research are presented and the influence of a number of technological parameters of the process implementation (concentration of solutions, temperature, duration) on the speed of formation and geometry of Ag and Ag-Au nanoparticles is analyzed. It is shown that bimetallic Ag-Au nanostructures with a diameter of 10-20 nm are formed by galvanic replacement. It was established that the size of the synthesized Ag-Au nanoparticles depends on the initial size of AgNPs and almost does not change after the formation of the bimetal. The basic technological scheme for the production of Ag-Au bimetallic nanoparticles is proposed. The economic part shows the calculation of research costs.