Naslov
Electrochemical and STM studies of FeS nanoparticles in NaCl model solutions

Autori
Marguš, Marija ; Batina, Nikola ; Milanović, Ivana ; Bura-Nakić, Elvira ; Ciglenečki, Irena

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, neobjavljeni rad, znanstveni

Skup
A COST Action ES0801 Workshop ; Voltammetry and GEOTRACES

Mjesto i datum
Šibenik, Hrvatska, 07.10.2012. - 09.10.2012

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Nije recenziran

Ključne riječi
FeS; nanoparticles; voltammetry; EC-STM

Sažetak
The scientific interest in nanoparticles (NPs) or nanomaterials (NMs) mostly derives from the dramatic change in physical and chemical characteristics that substances experience at reduced length scales (1–100 nm), but because of their dimensions they present potential risk in the terms of ecotoxcity1. Our understanding is also limited by the lack of efficient methods to characterize natural and synthetic NPs and further understanding of NPs interactions requires a greater understanding of the structure of the nanoparticles in their in-situ state. In order to get more insight in FeS nanoparticles (NPs) electrochemical behavior, in-situ Electrochemical Scanning Tunneling Microscopy (EC-STM)2 has been used for characterization and determination of FeS NPs at the Au(111) electrode in NaCl solutions. In parallel, voltammetric measurements at different electrode systems (Hg and Au) were conducted because the electrochemical methods can be successfully employed in characterization and determination of chalcogenide nanoparticles in model solution and natural waters3, 4. EC-STM has been used for the first time for characterization and determination of FeS NPs in NaCl electrolyte solution with an idea of getting more information related to attachment, adsorption, deposition and interaction between FeS NPs and functionalized electrode surfaces. Particle deposition was studied in relation to variations of applied and scanning electrode potentials in the range from 0.01 to -1.5 V vs. Ag/AgCl. EC-STM images, obtained on the Au(111) electrode, revealed the presence of FeS NPs which was accompanied with a drastic transformation of electrode surface topography during scanning potential from 0.1 V to -1.2 V. Majority of FeS NPs (diameter 2-5 nm) were detected around -0.3 V. EC-STM clearly revealed presence of FeS NPs on the Au(111) electrode surface which previously were detected by voltammetric measurements at the Hg electrode3. Combination of in-situ EC-STM and cyclic voltammetry as two different but complementary techniques appears to be a powerful tool for simple, selective, qualitative and quantitative chalcogenide NPs characterization of complex electrochemical systems such as NPs in the aqueous solutions.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

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