[Fluorescence studies of Eu ions adsorption on pseudo-boehmite colloidal particle surface]

Stable pseudo-boehmite sol was obtained by adding HNO3 as peptizing agent and adjusting pH to be 2.0. TEM result shows that the AlOOH colloidal particle size is about 60 nm. Field emission transmission electron microscope (FETEM) result shows that pseudo-boehmite colloidal particle is composed of 8 nm scaled AlOOH nanocrystals. The interaction of Eu3+ ions and colloidal AlOOH nanoparticle was investigated. The adsorption of Eu3+ ions on the surface of AlOOH nanocrystal was attributed to the chemical adsorption caused by electrostatic attraction. The photoluminescence characters of Eu3+ in AlOOH/Eu(NO3)3 composite sol system were investigated. The 529 nm emission intensity of Eu3+, I592, decreased with the increase in the molar ratio of AlOOH and Eu3+, RBoe/Re. The adsorption ratio (denoted R) and the adsorption density (denoted D) of Eu3+ ions on AlOOH colloidal particle surface was calculated from I592. The results show that the values of R and D increase with increasing RBoe/Re.