Dielectric and Catalytic Behavior of V₂O₅-Rich Glass-Ceramics Synthesized by Controlled Heat Treatment-Induced Crystallization

The need for innovative, sustainable materials for electrochemical devices and catalysts highlights V₂O₅-based materials as particularly promising. They can serve as cathodes for Li-ion, Na-ion, and all-solid-state batteries due to their high safety, energy density, and long life cycles. Additionally, they function as catalysts in oxidation reactions, especially fatty acid decarboxylation, which is crucial for biodiesel production—a renewable, lower-toxicity alternative to petroleum diesel that reduces greenhouse gas emissions and addresses environmental challenges. V₂O₅-rich glasses and glass–ceramics (GCs) stand out due to their dense, uniform microstructures and exceptional mechanical, thermal, electrical, dielectric, and catalytic properties. Furthermore, GCs are particularly interesting because they offer unique control over composition, crystallographic structure, and microstructure, including the type and quantity of crystalline phases within the residual glassy phase, all of which can be finely adjusted through heat treatment conditions such as temperature and duration. In light of these factors, this study examines how the controlled crystallization of V₂O₅-rich parent glass affects its structural, dielectric, and catalytic properties. The composition of prepared samples is analyzed using powder X-ray diffraction (PXRD), while their (micro)structural properties are characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy (SEM-EDS) and infrared attenuated total reflectance spectroscopy (IR-ATR). Dielectric properties are investigated via solid-state impedance spectroscopy (SS-IS) across a broad frequency range (0.01 Hz to 1 MHz) and temperature range (–90 °C to 210 °C). Additionally, catalytic activity in fatty acid decarboxylation is evaluated using thermogravimetric analysis and differential scanning calorimetry (TG/DSC). The results demonstrate significant improvements in both dielectric and catalytic performance, highlighting the versatile potential of V₂O₅-rich glass–ceramics for advanced electronic applications and sustainable biodiesel production.

This work is supported by the Croatian Science Foundation under the projects IP-2018-01-5425 and DOK-2021-02-9665 and partially funded by the European Union – NextGenerationEU.