Novel hybrid xerogel with CaF2: Tb3+ nanoparticles covalently embedded into silicon-oxygen network through sol-gel process

Abstract

In this work, Tb3+ doped CaF2 (CaF2: Tb3+) nanoparticles were synthesized with the silylant agent synthesized from meta-aminobenzoic acid and 3-isocyanatopropyltriethoxysilane as the surface modifier. The as-synthesized nanoparticles were covalently bonded to the silicon-oxygen network through a sol-gel process with tetraethyl orthosilicate (TEOS) as the precursor, resulting in the chemically bonded hybrid xerogel. The chemical doping makes the nanoparticles evenly dispersed in the stable hybrid system. The combined techniques SEM and EDX have confirmed the hybrid xerogel formed Si–O–Si network structure and the nanoparticles were successfully embedded into the Si–O–Si network. The efficient energy transfers from silylant agent to Tb3+ ions were observed in both the nanoparticles and hybrid xerogel, showing an obvious characteristic emission of Tb3+ ions. Both decay curves of nanoparticles and the hybrid xerogel were fitted as a double exponential decay, and the hybrid xerogel exhibited longer luminescent lifetime.