Solid-state synthesis of embedded single-crystal metal oxide and phosphate nanoparticles and in situ crystallization

JOURNAL OF COLLOID AND INTERFACE SCIENCE

卷:362

Article

Diaz, C.¹  Valenzuela, M. L.²  Bravo, D.¹  Dickinson, C.³  O'Dwyer, C.^3,4 

[1] Univ Chile, Fac Ciencias, Dept Quim, Santiago 3425, Chile

[2] Univ Andres Bello, Dept Ciencias Quim, Fac Ciencias Exactas, Santiago 8370147, Chile

[3] Univ Limerick, Mat & Surface Sci Inst, Limerick, Ireland

[4] Univ Limerick, Dept Phys & Energy, Limerick, Ireland

关键词: Embedded nanoparticles;    Electron microscopy;    Organometallics;    Nanomaterials;    Colloids;    Synthesis;    Metal oxide;    Phosphates;    Crystallization;   

DOI  :  10.1016/j.jcis.2011.05.066

来源: Elsevier

【 摘 要 】

A new solid state organometallic route to embedded nanoparticle-containing inorganic materials is shown, through pyrolysis of metal-containing derivatives of cyclotriphosphazenes. Pyrolysis in air and at 800 degrees C of new molecular precursors gives individual single-crystal nanoparticles of SiP2O7, TiO2, P4O7. WP2O7 and SiO2, depending on the precursor used. High resolution transmission electron microscopy investigations reveal, in most cases, perfect single crystals of metal oxides and the first nanostructures of negative thermal expansion metal phosphates with diameters in the range 2-6 nm for all products. While all nanoparticles are new by this method, WP2O7 and SiP2O7 nanoparticles are reported for the first time. In situ recrystallization formation of nanocrystals of SiP2O7 was also observed due to electron beam induced reactions during measurements of the nanoparticulate pyrolytic products SiO2 and P4O7. The possible mechanism for the formation of the nanoparticles at much lower temperatures than their bulk counterparts in both cases is discussed. Degrees of stabilization from the formation of P4O7 affects the nanocrystalline products: nanoparticles are observed for WP2O7, with coalescing crystallization occurring for the amorphous host in which SiP2O7 crystals form as a solid within a solid. The approach allows the simple formation of multimetallic, monometallic, metal-oxide and metal phosphate nanocrystals embedded in an amorphous dielectric. The method and can be extended to nearly any metal capable of successful coordination as an organometallic to allow embedded nanoparticle layers and features to be deposited or written on surfaces for application as high mobility pyrophosphate lithium-ion cathode materials, catalysis and nanocrystal embedded dielectric layers. (C) 2011 Elsevier Inc. All rights reserved.

【 授权许可】

Free