Synthesis and characterization of MgO-ZrO2 mixed oxides prepared by the sol–gel method

Abstract

Combining ceramic materials such as MgO and ZrO₂ can have a wide chemical and technological application. In this context, the sol–gel method is a very noble method for preparing mixed oxides, as it allows the control of their textural and surface properties. This paper aims to evaluate the structural and morphological properties of MgO-ZrO₂ mixed oxides as a function of their composition, for which solids of 10, 25, 50, 75, and 90% mol of ZrO₂ were synthesized by the sol–gel method. The obtained materials were characterized by N₂ physisorption, X-ray diffraction, scanning electron microscopy and diffuse reflectance, Fourier transform infrared, and Raman spectroscopy. The results showed that the textural properties of MgO improved by adding 25% ZrO₂, such that this solid showed the highest surface area (124 m²/g) and pore diameter of 12 nm. FTIR, RD-UV–Vis, and Raman spectra showed the presence of O–H chemical bonds due to the hygroscopic character of the materials. In contrast, XRD results showed MgO in the periclase phase and ZrO₂ mostly in the tetragonal phase. It was also observed that the bandgap energy increases slightly as a function of ZrO₂ content. On the other hand, SEM micrographs showed that the increase of ZrO₂ changes the morphology of the particles, size and shape.