Green development of samarium borosilicate glasses doped silica gel waste for stable orange colored visible host material

This study presents a new way to make luminescent glass doped with SiO₂ components using recycled silica gel waste from laboratories and ball milling and melt-quenching methods. A study is conducted on the optical, photoluminescence, and X-ray luminescence characteristics of glasses doped with recycled silica gel waste (RSGW); (69-Y)B₂O₃–18Li₂O–12BaO–YRSGW-1.0Sm₂O₃ (Y= 0–60 mol%) and Sm₂O₃-doped; (40-Y)B₂O₃–18Li₂O–12BaO–30RSGW-YSm₂O₃ (Y= 0–2 mol%). The glass samples undergo characterization using several spectroscopic techniques under standard ambient conditions. The density and refractive index of the YSilicagelSm glasses increase, while their molar volume value decreases with the increase in RSGW content in the glass system. Furthermore, the absorption spectra display the hypersensitive transitions ⁶H_5/2→⁶P_3/2 and ⁶H_5/2→⁶F_7/2 in the visible and near-infrared ranges, respectively. The glasses exhibit four prominent transitions that are indicative of the Sm³⁺ ion as a result of photoluminescence and X-ray luminescence. Among these, the ⁴G_5/2→⁶H_7/2 (at 600 nm) transition is the most intense. Photoluminescence and X-ray luminescence suggest the highest emission intensity occurs in the host composition containing 30 mol% RSGW. According to the CIE 1931 chromaticity diagram, this glass produces a reddish-orange illumination. A further experiment was prepared with a host glass (40-Y)B₂O₃–18Li₂O–12BaO–30RSGW-YSm₂O₃ with varying Sm₂O₃ concentrations. The results from both luminescence experiments support that the concentration of Sm₂O₃ increases up to 1.0 mol% and then decreases, which is the appropriate quenching concentration of Sm³⁺. This not only offers another way to repurpose waste but also presents interesting novel possibilities for materials science and photonics research.