engleski

Surface properties of cerium(iv) oxide / aqueous electrolyte solution interface

When colloid particles and nanoparticles come in contact with aqueous electrolyte solution, the ions between solution and interface are redistributed, the amphoteric surface groups are protonated and deprotonated and the electric interfacial layer is formed. Surface properties of colloid particles and nanoparticles depend on surface structure, electric interfacial layer formation and surface reactions. Cerium(IV) oxide nanoparticles are used in various branches of industry due to their specific properties, as catalysts, in fuel cells and in medicine as oxidizing and reducing agents. Synthesis of cerium(IV) oxide nanoparticles is relatively simple and particles of controlled shape and size can be prepared. Nanoparticles of cerium(IV) oxide are synthesized by hydrolysis of cerium(III) nitrate hexahidrate [1] and purified of residual ions. For characterization of synthesized nanoparticles transmission electron spectroscopy (TEM), dynamic light scattering (DLS), X-ray diffraction (XRD) and specific surface analysis (BET) were used. Surface properties of cerium(IV) oxide are determined experimentally. The influence of pH and electrolyte concentration on surface properties of synthesized cerium(IV) oxide nanoparticles is investigated. Electrokinetic potential and isoelectric point of cerium(IV) oxide nanoparticles are determined by electrophoresis method. Surface charge density is determined by acid-base potentiometric titrations and mass titrations [2]. Surface potential of cerium(IV) oxide planes is determined by potentiometric titrations using single crystal electrodes containing cerium(IV) oxide of different orientations. Thermodynamic parameters (equilibration constants) which describe surface reactions are calculated from experimental data. Surface complexation model was used [3].

ceria ; nanoparticles ; surface charge ; surface properties

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