Fabrication of NiCo2O4@CeO2 core@shell nanotubes with enhanced catalytic performances

Abstract

Highly uniform NiCo₂O₄@CeO₂ core@shell nanotubes with tunable CeO₂ shell thicknesses have been successfully synthesized by a multi-step wet chemistry process. The use of NiCo₂O₄ hollow tubes coupled with CeO₂ nanocrystals is the result of consideration from the view points of the components, shape and structure-effects needed for a catalyst. In the following catalytic test of CO oxidation, the as-obtained NiCo₂O₄@CeO₂ core@shell nanocatalysts exhibit obvious component-, shape- and hybrid structure-dependent catalytic performances. Especially, the NiCo₂O₄@CeO₂-2 sample has shown the highest activity, which makes it an ideal “noble metal-free” nanocatalyst.