Phosphate Glasses and Glass-Ceramics: Structural, Optical, Photocatalytic, and Dielectric Insights

Advancing multifunctional materials for environmental and technological applications requires the design of systems that combine structural stability with enhanced optical, photocatalytic, and dielectric properties. In this context, phosphate-based glasses and glass-ceramics within the ZnO–Na₂O–P₂O₅–TiO₂ system were investigated, with particular emphasis on the role of TiO₂ incorporation. Controlled thermal treatments were employed to induce partial devitrification, yielding crystalline phases finely dispersed within a residual glassy matrix. Structural and microstructural characterizations confirmed the amorphous nature of the as-prepared samples and their progressive crystallization upon heating, highlighting the contribution of Ti–O–P linkages to network reinforcement.

Optical analyses demonstrated a noticeable enhancement in UV absorption and a red shift of the absorption edge with increasing TiO₂ content, coupled with a slight narrowing of the optical band gap. These modifications indicate improved light-harvesting efficiency, which is beneficial for photocatalytic applications. Photocatalytic activity was evaluated through the degradation of methylene blue under UV–visible irradiation. All studied compositions exhibited photocatalytic effects, with higher TiO₂ concentrations accelerating the degradation process, thus confirming the catalytic role of titanium.

Dielectric investigations revealed frequency-dependent permittivity, with significant improvements observed upon TiO₂ addition. The reduction of polarization losses and stabilization of dielectric behavior further emphasized the potential of these materials for electronic and energy-related uses.

Overall, these results demonstrate that TiO₂-doped phosphate glasses and glass-ceramics successfully integrate optical, photocatalytic, and dielectric functionalities, making them promising candidates for advanced applications in environmental remediation and dielectric technologies.