The photoluminescence of rhodamine B encapsulated in mesoporous Si-MCM-48, Ce-MCM-48, Fe-MCM-48 and Cr-MCM-48 molecular sieves

Photophysical and photochemical properties of rhodamine B molecules encapsulated into various mesoporous molecular sieves were investigated by absorption and emission spectra and fluorescence decay. The different fluorescence properties were observed within different RhB/Me-MCM-48 (Me = Ce, Fe, Cr) composites. There were larger blue shifts in fluorescence spectra when RhB included in Ce-MCM-48 than that in Fe-MCM-48 and Cr-MCM-48. However, the much larger electron transfer efficiencies from excited dye molecules to iron and chromium oxide occurred within the system of RhB/Fe-MCM-48 and RhB/Cr-MCM-48 than that within the system of RhB/Ce-MCM-48. The effects of Ce-containing amounts on the fluorescence properties were also investigated in detail.