Photosensitization of europium ions by silver clusters in zeolite

Confinement of Highly Luminescent Silver Nanoclusters in FAUY Zeolite: A Study on the Formation Effects of Silver Nanoclusters and the Sensitization of Tb3+

“…On the other hand, the quenching of nonradiative processes of Ag NCs by isolating them from water molecules due to Tb 3+ co-doping also contributed to the prolonged lifetime. 16 Furthermore, the XPS measurement was carried out to detect the chemical state and chemical shift of Ag before and after Tb 3+ loading. It can be seen from Figure 8 that the highresolution X-ray photoelectron spectra of Ag 3d present two bands, which correspond to the photoelectron peak of Ag 3d 5/2 and Ag 3d 3/2 , respectively, 52 and the binding energies for each sample are summarized in Table S1 (in the Supporting Information).…”

“…This is reasonable because fewer Ag NCs were formed with increasing Tb 3+ loading amount based on the above discussion, which can avoid the possible concentration quenching and therefore lead to a prolonged lifetime of Ag NCs. On the other hand, the quenching of nonradiative processes of Ag NCs by isolating them from water molecules due to Tb 3+ co-doping also contributed to the prolonged lifetime …”

“…Furthermore, the DRS measurement was carried on FAUY-20Ag as a representative, which showed four absorption bands at 213, 280, 310, and 450 nm (see Figure S1 in the Supporting Information). The strong absorption band at 213 nm belongs to the 4d 10 → 4d 9 5s 1 electronic transition of the isolated Ag + located at specific sites within FAU or LTA zeolite frameworks. ,, The absorption bands at 280 and 310 nm that result in the green emission can be attributed to Ag 3 n + clusters, while the absorption band at 450 nm is due to the surface plasmon resonance of silver nanoparticles. , Figure S2 (in the Supporting Information) shows the corresponding TEM and HRTEM images, from which the silver nanoparticles with diameters larger than 3.0 nm can be observed besides those smaller ones. The inset HRTEM image in Figure S2b displays a lattice space of 0.2291 nm for the nanoparticles in FAUY-20Ag, which is in line with the silver nanoparticle (111) facet. , …”

“…Recently, highly luminescent Ag NCs have been successfully prepared inside the well-defined cages of zeolites. After thermal treatment, electron beam, or X-ray irradiation on the Ag + -exchanged zeolites with different topology structures, the Ag NCs like Ag 2 + , Ag 3 n + , and Ag 6 m + can be formed according to the respective cage size. ,,, The growth dynamics of luminescent Ag NCs have been studied recently through the modified Auger parameter (Ag 3d 5/2 + Ag M 4 N 45 N 45 ) by monitoring the growth of silver species under Al Kα exposure from silver ions to luminescent Ag NCs and then metallic silver nanoparticles in FAUX and FAUY zeolites. It indicated that the growth rate of silver species follows a noncooperative Hill–Langmuir type behavior and is different in FAU zeolites, depending on the mobility of Ag + in the framework .…”

“…In addition to the highly bright, tunable, and sensitive emission properties, recent research studies indicated that the Ag NCs are also efficient sensitizers for f–f transition rare earth (RE) ions like Eu 3+ , Dy 3+ , and Er 3+ when confined inside zeolites. ,,,− Formation of Ag NCs in RE-loaded zeolites can not only achieve enhanced emission intensity but also adjust luminescence performance by combining the visible emissions of Ag NCs and RE ions. For instance, variations of the Eu 3+ : 5 D 0 → 7 F 0‑4 transition probability in Ag NCs and Eu 3+ dual-loaded FAU zeolites were investigated and white light emissions were achieved successfully. , The emission intensity due to the Dy 3+ : 4 F 9/2 → 6 H 13/2 transition can be more than 50 times enhanced in the presence of Ag + ions, and white light emission was realized through the combination of blue emission from Ag + , yellow emission from Dy 3+ , and red emission from Ag NCs .…”