An Interfacial Europium Complex on SiO2 Nanoparticles: Reduction-Induced Blue Emission System

摘要

In this study, Eu-coated SiO2 nanoparticles have been prepared, consisting of an interfacial complex of Eu and 1,10-phenanthroline (phen) at the solid surfaces of the SiO2/Eu nanostructures. The as-prepared SiO2/Eu/phen nanoparticles exhibits sharp red emission via energy transfer from the phen to the Eu^III. After sintering at 200 °C in air, the emission is tuned from red to blue. The blue emission is originated from Eu^II. This reduction-induced emissive phenomenon resulted from the electron-donating environment created by the surrounding phen and SiO2, which is the first reported fabrication of a stable Eu^II-based emissive material using mild conditions (reaction in air and at low temperature) and an organic-inorganic hybrid nanostructure. The existence of two different stable oxidation states with characteristic emissions, blue emissive Eu^II and red emissive Eu^III, suggests significant potential applications as novel luminescent materials with inorganic-organic hybrid structures.