Magnetic and luminescent dual-functional SiO2 beads created through controlled sol-gel process

Zhongsen Yang*

State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, P. R. China

Adv. Mater. Lett., 2011, 2 (3), pp 195-199

DOI: 10.5185/amlett.2011.1212

Publication Date (Web): Apr 08, 2012

E-mail: zsyang@sdu.edu.cn

Abstract


A controlled sol-gel approach was developed to encapsulate luminescent CdTe and magnetic Fe3O4 nanocrystals (NCs) into SiO2 beads. The preparation procedure included the preparation of SiO2-coated Fe3O4 NCs, the attachment of the CdTe NCs on the SiO2-coated Fe3O4 NCs, the assembly of the CdTe NCs-attached Fe3O4 NCs, and the growth of a SiO2 shell. To prevent the photoluminescence (PL) quenching, Fe3O4 NCs were coated with a thin SiO2 layer before encapsulating into SiO2 beads together with CdTe NCs. The CdTe NCs retained high PL efficiency (30 %) in dual functional SiO2 beads. These SiO2 beads also revealed superparamagnetic behavior. The result would be utilizable for further application because of their high PL efficiency and magnetic property. The strategy described here should give a useful enlightenment for the design and fabrication of multiple functional SiO2 beads.

Keywords

Bi-functional SiO2 beads, iron oxide magnetic nanoparticlels, semiconduductor nanocrystal

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