Highly efficient degradation of methylene blue with silver-based inorganic oxide glass catalysts

Water contamination by synthetic dyes, such as methylene blue (MB), poses a significant environmental challenge due to their chemical stability and resistance to conventional waste water treatments. In this study, a series of silver-doped phosphate and borate glasses were synthesized via typical melt-quenching methods and evaluated for their photocatalytic efficiency in MB degradation under UV and visible light. The most significant result is the superior performance of silver metaphosphate (AgPO 3 ), which achieved 86% MB removal under visible LED irradiation and 64% removal in the dark within 60 minutes, outperforming all other investigated compositions, including silver-free sodium phosphate, silver-rich iodide-phosphate, and silver borate glasses. This confirms its dual catalytic activity under both light-assisted and non-irradiated conditions. Characterization results indicate that this enhanced performance is directly associated with the formation and homogeneous dispersion of Ag 0 nanoparticles within the phosphate glass matrix, which promotes strong plasmonic activation and efficient generation of reactive oxygen species (ROS), leading to accelerated dye degradation. Furthermore, comparative analysis clearly demonstrates that the phosphate network provides the most favourable environment for nanoparticle stabilization and catalytic activity among the studied systems. The AgPO 3 glass also maintained stable photocatalytic efficiency over multiple reuse cycles, confirming its structural and functional durability. Overall, AgPO 3 exhibits the highest quantified degradation efficiency, combined with strong activity in both dark and illuminated conditions and excellent reusability, highlighting its potential as an effective and stable photocatalyst for wastewater treatment applications.