An efficient UV converted blue-emitting Lu 2 CaGeO 6 :Bi 3+ persistent phosphor for potential application in photocatalysis

Abstract Nowadays, exploring new photonic materials that can efficiently convert the invisible light into the visible light have attracted tremendous attention in the catalytic field. Here, we design and prepare a kind of Bi 3+ doped Lu 2 CaGeO 6 phosphor by using the solid-state reaction at 1250 °C in air for 5 h. The structural analysis, which is based mainly on the powder X-ray diffraction (XRD) spectra, shows that the as-prepared Bi 3+ doped Lu 2 CaGeO 6 phosphors belong to a trigonal structure with a space group of R 3 (No. 146). The photoluminescence (PL) results reveal that changing the excitation wavelengths from 240 nm to 340 nm does not change the emission sharp and position of the Bi 3+ doped samples, allowing the maximum emission intensity to keep at 420 nm. Except for the fluorescence, up exposure to the UV light ( e.g. , 254 nm), the Lu 2 CaGeO 6 :Bi 3+ phosphors can also exhibit the Bi 3+ -related blue afterglow luminescence. The longest afterglow duration that corresponds to the 1.5%Bi 3+ doping content in the Lu 2 CaGeO 6 crystal host can last 30 min in the dark. After comparing the Bi 3+ -related blue afterglow band to the band gap of TiO 2 semiconductor that corresponds to the wavelength of 387 nm, it clearly indicates us that the Bi 3+ doped Lu 2 CaGeO 6 phosphors can serve as a continous excitation source for light-sensitive TiO 2 semiconductor for photocatalysis application.