Preparation of the up-conversion glass-ceramics and its synergistic effect on the photocatalytic degradation of photocatalyst

The B2O3-CaF2-Bi2O3 glass-ceramics precipitating CaF2 crystal were prepared by high temperature melting method. The effects of heat treatment schedules, B2O3: Bi2O3 ratio on crystallization behavior and microstructure of base glass were studied. Up-conversion glass-ceramics with Yb3+ as sensitizer and Tm3+ as activator were also prepared, and the effects of Tm3+ doping on their crystallization, microstructure, and up-conversion lumines-cence performance were analyzed through DSC, XRD, SEM, TEM and PL. To improve further the up-conversion luminescence peformance, Li+ doped up-conversion glass-ceramics and the effect of Li+ doping amount were prepared and explored. The results indicated that the up-conversion luminescence intensity reached its highest when the doping concentrations of Yb3+, Tm3+ and Li + ions were 10 mol%, 0.1 mol% and 6 mol%, respectively. To explore the effect of the prepared up-conversion glass-ceramics on the photocatalytic degradation of ZnIn2S4-Ag-LaFeO3 photocatalyst to dye contaminated model methylene blue (MB), the photocatalytic degra-dation experiment was carried out by mechanical mixing of up-conversion glass-ceramics and photocatalyst. It was found that the addition of up-conversion glass-ceramics increased the photocatalytic degradation efficiency by 25% under near-infrared light and 7.3% under full spectrum.