Photoreduction of Europium (III) in Sol-Gel Derived Inorganic-Organic Hybrid Materials

Abstract

Eu2+-doped inorganic-organic hybrid materials, which are potentially suitable for a tunable laser in the near ultra violet and blue region, were prepared through the photoreduction of Eu3+ ions in the materials under the irradiation of the fourth harmonic wave light (266 nm) of the Nd:YAG laser. The hybrid materials doped with Eu3+ ions were prepared from Si(OCH3)4, CH3Si(OCH3)3, EuCl3 and chloropropyltrimethoxysilane (CPTM). After the prehydrolized silica sol was added to the Eu3+-containing solution, Eu3+-doped transparent inorganic-organic hybrid material was obtained by drying at 50°C. The emission peak around 450–475 nm due to the charge transfer transition (5d-4f) of Eu2+ ions increased with the laser irradiation time. Eu3+ ions were effectively photoreduced to Eu2+ ions in pore-free materials prepared at high CPTM to Eu3+ ratios. Eu2+ ions were generated by the photodecomposition of the bond between Eu3+ and Cl (Cl− or Cl(CH2)3 in CPTM).