Efficient encapsulation of LaCoO3 perovskite in mesoporous silica induced by a chelating template

• LaCoO3/mesoporous silica composites have been successfully constructed.
• A triprotic acid was used both as metal chelating agent and structure-directing agent.
• The as-synthesized LaCoO3 possesses a single perovskite structure.
• We provide a simple approach to encapsulating composite metal oxides into mesopores.

A novel and facile chelating-template route for encapsulation of nanosized LaCoO3 into mesoporous silica has been investigated. An amphipathic triprotic acid, which has capability to prepare perovskite LaCoO3 powder through Pechini-type method, directs the construction of silica host and thereby fabricates LaCoO3/mesoporous silica composites. Powder X-ray diffraction and X-ray photoelectron spectroscopy analyses were undertaken to determine the formation of the perovskite crystalline phase. Electron microscope and nitrogen adsorption–desorption analyses were carried out to elucidate the structural features of the host–guest composites. It was demonstrated that ultrafine guest LaCoO3 nanoparticles with perovskite rhombohedral phase were formed after calcination, and the host silica skeleton remained short-range ordered mesoporous feature after implantation. This study therefore presents a potential simple approach to encapsulating well-dispersed composite metal oxide in mesoporous silica.

Schematic illustration of HED3A-assisted introduction of cobalt and lanthanum cations into mesopores.Figure optionsDownload as PowerPoint slide