Naslov
Application of the surface potential data to elucidate interfacial equilibrium at ceria/aqueous electrolyte interface

Autori
Preočanin, Tajana ; Namjesnik, Danijel ; Mutka, Sanela ; Kallay , Nikola

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
ISSHAC-9 Proceedings / Drach, Mateusz - : Polish Chemical Society, 2015, 41-41

ISBN
978-83-7784-669-8

Skup
Surface Heterogeneity Effects in Adsorption and Catalysis on Solids, ISSHAC-9

Mjesto i datum
Wrocław, Poljska, 17.07.2015. - 22.07.2015

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
ceria oxide ; single crystal electrode ; surface potential ; surface complexation ; nanoparticles

Sažetak
Surface reactivity in aqueous dispersion is expressed in two ways: reaction of surface sites with ions and interactions between two surfaces when they approach each other. Both processes were studied for ceria nanoparticles considering the role of surface structure on electrical charging. Ceria (cerium(IV) oxide) nanoparticles play an important role in industrial processes, bio- medical applications, production of renewable energy and catalysis. Additionally, the toxicity of ceria nanoparticle has been reported. Interfacial properties of ceria are directly related to the reactivity of surface sites which is important to be understand. In order to characterized ceria nanoparticle behavior the surface properties were measured and related to the crystal structure. Cubic ceria nanoparticles were prepared by oxidation of cerium(III) nitrate [1]. The properties of purified ceria nanoparticles (size, shape, inner structure, colloid stability) were measured. It was found that after preparation primary ceria particles (5 nm) undergo fast aggregation forming larger aggregates (20-100 nm). The aggregation takes place mostly by interaction of the (001) ceria crystal planes. Surface charge density and point of zero charge of prepared ceria nanoparticles were measured by means of the potentiometric acid- base and mass titrations [2, 3]. Electrokinetic potential was measured by electrophoresis. Surface characterization of colloid or nano particles exhibiting different crystal planes to the aqueous electrolyte solution provides some kind of average surface properties (i.e. average surface charge densities and electrokinetic potential). Analysis of well-defined crystal surfaces which form colloid or nano particles leads to better understanding of surface reactions and mutual interactions of individual crystal planes on average surface properties of particles. For that purpose the inner surface potential of (001) and (111), as a function of pH and ionic strength, was measured by single crystal electrode [4]. Inner surface potential affects directly the state of ionic species bound to certain surface plane and is thus essential parameter governing interfacial equilibrium. The results were interpreted by means of Surface Complexation Model and Multisite Complexation Model.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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