Synthesis and study of nanosized gadolinium oxide modified by zirconium oxide


Niftaliev S. I. , Kuznetsova I. V. , Lygina L. V. , Tuneekov V. Y. , Saranov I. A. , Tolkacheva A. A. , ...Daha Fazla

SOLID STATE SCIENCES, cilt.110, 2020 (SCI İndekslerine Giren Dergi) identifier identifier

Özet

A method for the fabrication of nanosystems Gd2O3, 90%Gd2O3-10%ZrO2, 80%Gd2O3-20%ZrO2, 70% Gd2O3-30%ZrO2 from salt solutions using freeze-drying is studied. Using the TEM method, the particle sizes (18-40 nm) after annealing at 700 degrees C are estimated. In the Gd2O3-ZrO2 system the phases of Gd2O3 and Gd2Zr2O7 are present. The acid-base properties of the surface are evaluated using the Hammett indicator method: there are BrOnsted acid sites with pK(a) = 1.7; 2.1; 3.46; 5.2 and the Bronsted base site with pK(a) = 7.4. The addition of zirconium oxide to gadolinium oxide sharply increases the value of specific adsorption and donor surface properties. Using DSC method, the process of acid-base catalysis as exemplified by thermodestruction of activated carbon in the presence of the systems Gd2O3, Gd2O3-ZrO2 is assessed. Decomposition of activated carbon in the presence of Gd2O3, 90%Gd2O3-10%ZrO2, 80% Gd2O3-20%ZrO2, and 70%Gd2O3-30%ZrO2 proceeds faster. The activation energy of the processes decreases from 1.67 to 0.56 kJ/mol, while the thermal effect and mass loss increase.