EFFECT OF TIME EXPOSURE ON THERMOLUMINESCENCE GLOW CURVE FOR UV-INDUCED ZRO₂:MG PHOSPHOR

Abstract

In this research, the effect of magnesium (Mg) impurity on thermoluminescence (TL) response of ZrO2 phosphors is studied experimentally. In the experimental procedure, ZrO2:Mg phosphors in the powder form were synthesised by the sol-gel method. The obtained hydrogel was dried in air and then calcinated in air at 1200°C for 5 h and next was annealed at 250°C for 2 h. Sample characterisations were done by X-ray diffraction and scanning electron microscopy. Obtained materials had monoclinic phase and porous microstructure. Then, known amounts of ZrO2:Mg powder were exposed to ultraviolet lamp from 0.5 to 120 min. The TL peaks were obtained at the same temperature as 75, 137 and 260°C, respectively. Adding Mg to pure zirconia caused to increase TL intensity and shift peaks related to pure zirconia. The TL peaks of the pure zirconia were seen at the 83, 132 and 235°C. Finally, ZrO2:Mg TL experimental results show the linear dose response, high stability and less fading.

UiO-66 MOF-Derived Ru@ZrO2 Catalysts for Photo-Thermal CO2 Hydrogenation

“…Results also showed that the calcination treatment caused a slight change in the ruthenium content from 0.34 wt.% in Ru 0.10 @ZrO 2 -400 • C to 0.26 wt.% and 0.24 wt.% for samples Ru 0.10 @ZrO 2 -500 • C and Ru 0.10 @ZrO 2 -600 • C, respectively. In the case of the lowest Ru to Zr molar ratio, the Ru content diminished to 0.04 wt.% for Ru 0.03 @ZrO 2 -600 • C. [36][37][38]. Lippi et al [31] demonstrated, by operating XRD, the importance of the monoclinic ZrO2 phase transitions during thermal treatment to stabilize Ru and obtain active CO2 methanation catalysts.…”

“…X-ray patterns in Figure 2b and Figure S3 reveal the presence of monoclinic ZrO 2 in the Ru@ZrO 2 -600 • C samples. Meanwhile, Ru@ZrO 2 -400 • C and Ru@ZrO 2 -500 • C contain cubic ZrO 2 [36][37][38]. Lippi et al [31] demonstrated, by operating XRD, the importance of the monoclinic ZrO 2 phase transitions during thermal treatment to stabilize Ru and obtain active CO 2 methanation catalysts.…”