Core-satellite is one of the most powerful superstructures since it leads to enhanced or completely new properties through compatible combination of each component. Here we create a novel ceria-based core-shell-satellite supersandwich structure with near-infrared (NIR) light manipulated catalytic activity by integrating the upconversion luminescent and catalytic functionality of CeO2 nanoparticles. Specifically, lanthanide-doped octahedral CeO2 nanoparticles (o-CeO2) are coated with silica layer (o-CeO2@SiO2) to enhance their luminescence intensity. The pH-dependent catalytic active cubic CeO2 nanoparticles (c-CeO2) are then assembled on the surface of o-CeO2@SiO2 to form the supersandwich structure (o-CeO2@SiO2@c-CeO2) following a classic chemical reaction. The upconversion quantum yield of o-CeO2 in this nanostructure can be nearly doubled. Furthermore, under NIR light irradiation, the o-CeO2@SiO2@c-CeO2 supersandwich structure based composite catalyst displays superior catalytic activity in selective reduction of aromatic nitro compounds to corresponding azo compounds, and the composite photocatalyst can be easily recycled for several times without significant loss of catalytic activity. This strategy may serve as a universal method for the construction of multifunctional nanostructures and shed light on the green chemistry for chemical synthesis.
CeO 2 , one of most attractive rare earth oxides, that displays outstanding properties such as excellent catalytic activity, marked chemical/thermal stability and the ability for the formation/diffusion of oxygen vacancies, is widely used as the support for noble metal catalysts to improve the conversion efficiencies of catalytic reaction. In the past several decades, noble metal/ceria-based composites have been extensively employed in CO oxidation, water gas shift reaction, NO x reduction and solid oxide fuel cell, suggesting their important roles in green energy and environmental remediation. Normally, the complicated interaction between CeO 2 and noble metals has great impact not only on the conversion rates of catalytic reactions, but also on the stability, activity and selectivity of the catalysts. This review focuses on the structures of the noble metal/ceria-based composition, including the conventional structure and novel structure. Based on novel structure, such as core-shell, yolk-shell, core-sheath, lamellar structure, the interaction between noble and ceria nanomaterials and the influence of the catalytic ability on this kind of interaction were all summarized. What's more, the different structure features and synthetic methods of the catalyst, the application of the catalytic characteristic and the influence of the catalytic ability on composite structure were also systematic discussed. The researches in noble metal/ceria-based compositions hold great promise in the synthesis of different structured catalysts with abilities to manipulate catalytic reactions in more economic and efficient ways.
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