Photoluminescent properties of MCM-41 molecular sieves

Decay dynamics of blue–green luminescence in meso-porous MCM-41 nanotubes

“…2. The PL peak energy is about 2.5 eV, similar to that in previous studies [9,[13][14][15]. The PL bands in silica materials have been associated with the structural point defects, such as NBOHCs, E' centers, twofold coordinated silicon centers, silanone and dioxasilyrane groups, etc.…”

“…Since the discovery of the M41S-type meso-porous materials in the early 1990s, extensive studies have been devoted to investigations of their basic properties and synthetic routes. Recently, some work has been carried out on the optical properties of mesoporous materials [9][10][11][12][13][14][15]. Studies of the optical properties of meso-porous materials not only investigate the nature of the materials and structural defects but also provide useful information for extending their applications to optical devices.…”

“…The red PL (1.8-2 eV) in MCM-41 has been commonly associated with an oxygen-related defect site, the nonbridging oxygen hole center (NBOHC) [9][10][11]. However, a variety of structural models such as E' centers [9], peroxy radicals (POR) [9], self-trapped excitons [12], two-fold coordinated silicons [13,15] and Si-OH surface complexes [14], have been suggested to explain the blue-green (2.4-2.7 eV) PL in MCM-41. Although some work has been devoted to the blue-green luminescence in MCM-41, the details of the mechanism and dynamics properties have not yet been established.…”

Identification of the silver state in the framework of Ag-containing zeolite by XRD, FTIR, photoluminescence,109Ag NMR, EPR, DR UV-vis, TEM and XPS investigations

“…3). The spectral distribution of the SiBEA photoluminescence obtained at 249 nm excitation light shown in Figure 3 is very similar to that recently reported for siliceous MCM-41 and amorphous silica [26]. The emission bands at 400 and 645 nm are likely due to surface defects associated with SiO-and/or SiOH groups, in agreement with earlier reported data [27].…”

Influence of the incorporation of metals on the optical properties of MCM-41

“…On the other hand, the blue-green PL has been ascribed to the Si-OH surface complexes [17,18] and two-fold-coordinated silicon centers (Si 0 2 ) [13][14][15]. However, only a very limited number of papers have been devoted to the study of aluminosilicate MCM-41 (denoted as Al-MCM-41) [20][21][22][23]. Mary et al [21] performed the first PL study on Al-MCM-41 and found that the emission of aluminosilicate MCM-41 appeared to be correlated with the presence of the aluminum framework.…”