Adsorption of inorganic ions at the titania/electrolyte solution interfaces has been studies using a radioisotopic technique. Adsorption evaluated from uptake of radioactivity from the solution is compared with that obtained from sediment radioactivity.
The surface charge and adsorption densities of Na+ and Cl– ions at the zirconium dioxide/electrolyte interface have been determined as a function of pH for 0.1, 0.01 and 0.001 M solutions of NaCl. Using potentiometric titration of the surface hydroxy groups, it was found that the point of zero charge occurred at pH 4.3±0.15. The results are discussed in terms of site binding model of the electric double layer. The ionization and complexation constants have also been determined.
Authors:W. Janusz, W. Staszczuk, A. Sworska, and J. Szczypa
The results of experimental studies of the adsorption of ions at the cadmium oxide/electrolyte solution interface are presented. On the basis of kinetic changes in the concentration of cadmium, hydroxide, and sulfate ions in the solution, the processes occurring in this system are discussed. It was found that cadmium oxide is transformed into the hexagonal form of cadmium hydroxide. The surface charge data for cadmium oxide/aqueous Na2SO4 are presented.
Authors:V. Sydorchuk, W. Janusz, S. Khalameida, E. Skwarek, J. Skubiszewska-Zięba, R. Leboda, and V. Zazhigalov
Deposited zirconium phosphate samples on the base of silica and titania have been prepared using the sol–gel and mechanochemical methods. Porous structure, phase composition, and electrokinetic parameters have been studied by means of nitrogen adsorption–desorption, XRD, DTA-TG, FTIR, electrophoresis, and potentiometric titration. The compositions possess varied parameters of porous structure, structure of deposited phase, and electrokinetic properties depending on support nature and synthesis conditions.
Authors:E. Skwarek, S. Khalameida, W. Janusz, V. Sydorchuk, N. Konovalova, V. Zazhigalov, J. Skubiszewska-Zięba, and R. Leboda
Mechanochemical activation of individual V2O5, MoO3 and mixed vanadium-molybdenum oxide system in various media (air, water, and ethanol) has been studied. Powder X-ray diffraction, nitrogen adsorption–desorption, thermogravimetric and chemical analysis, FTIR and Raman spectroscopy, and scanning electron microscopy have been used for research of prepared milled samples. The electrokinetic properties (dependence zeta potential—pH, position of isoelectric point) of individual V2O5, MoO3 and mixed vanadium–molybdenum oxide system, synthesized via mechanochemical treatment in various medium, in aqueous solutions of electrolytes also have been determined. Initial, milled, and spent samples are characterized with the help of XRD, FTIR and Raman spectroscopy, and SEM and adsorption of nitrogen. The catalytic properties of vanadium–molybdenum oxide composition activated in different media have been investigated in reaction of oxidation dehydrogenation of propane.