Preliminary structural characterization of ceria–titania polymorphic mixtures achieved by high-energy ball milling

High-energy ball milling is a simple and eco-friendly technique that has gained increasing popularity in recent years. This one-pot method of synthesis allows for the preparation of solid materials from a green perspective, avoiding multiple and complex steps, the use of solvents and the extreme pressure and temperature conditions commonly employed. Due to its multiple advantages, high-energy ball milling can make structural and surface modifications within the solid matrix according to the physicochemical properties needed, such as defect accumulation, polymorphic transformations, grain boundaries, amorphization, particle refinement and increases in specific surface area and ion mobility. In this regard, ceria–titania mixtures were obtained using several high-energy ball milling conditions (varying the metal oxide concentration, ball-to-powder ratio, time and rotational speed). The crystal structures created by the milling process were studied by means of X-ray Powder Diffraction (XRPD), including cerianite, anatase, rutile and high-pressure TiO₂ (II) formation. Moreover, the crystallite sizes and the specific surface area (S_BET) values were estimated using the Scherrer equation and N₂ physisorption (BET method), respectively. According to this preliminary study, the materials generated through this sustainable, cost-effective and easy-to-scale technique could be useful as catalyst supports for different metal nanoparticles or could act as catalysts in a variety of applications, e.g., oxidation and photocatalytic reactions in both the liquid and gas phases.