“Nanostructured surfaces”

Modification of the silicon surface by metal nanoparticles by ultrasound galvanic replacement
Shepida M.V.1, Kuntyi O.I.1, Korniy S.A.2
1 Department of Chemistry and Technology of Inorganic Substances, Lviv Polytechnic National University. Bandera Str., 12, Lviv-79013, Ukraine.
E-mail: maryana_shepida@ukr.net
2 Physico-Mechanical Institute of NASU. Naukova, 5, Lviv-79060, Ukraine

Galvanic replacement (GR) is an efficient method for modifying the silicon surface with metallic nanoparticles and nanostructures [1]. Processes occur by electrochemical mechanism, which can be represented by the following total reaction equation:
n Si + 4 M(+n)  n Si(+4) + 4 M.
The spontaneity passage of the processes, which occur in the anode and cathode sections, is largely due to the diffusion factor. This complicates the deposition of metal nanoparticles (MNPs) of a given geometry and their uniform distribution on the substrate surface. So, the aim of this work is to establish the effect of ultrasound on the controlled formation of MNPs (M = Ag, Au, Pd, Pt) on a silicon surface by the galvanic replacement method.
The dependence of the geometry of deposited MNPs on ultrasound frequency and specific power has been established. The efficiency of GR in the field of pulsed ultrasound on the formation of metal nanoparticles of uniform shape and size on a silicon surface is shown. The optimal conditions of ultrasound galvanic replacement (electrolyte composition, ultrasound parameters and process duration) are proposed for obtaining Si/MNPs nanostructures in solutions of hydrated and complex ions of renewable metals.

Acknowledgment
This work was carried out with the partial financial support of the National Research Foundation of Ukraine. Project registration number: 2020.02/0309.
  
1.	Kuntyi O.I., Zozulya G.I., Shepida M.V., Nichkalo S.I. Deposition of nanostructured metals on the surface of silicon by galvanic replacement: A mini-review // Voprosy Khim Khim Tekhnol.-2019.-3.-P. 74-82.
2.	Lahiri A., Kobayashi S.-I. Electroless deposition of gold on silicon and its potential applications: review // Surf Eng.-2016.-32.-P. 321-337.