Facile synthesis of Ag@CeO2 core–shell plasmonic photocatalysts with enhanced visible-light photocatalytic performance

Novel Ag@CeO 2 core–shell nanostructures with well-controlled shape and shell thickness were successfully synthesized via a green and facile template-free approach in aqueous solution. As-prepared samples were characterized by high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible diffuse reflection spectroscopy (DRS), electron spin resonance (ESR) and photoluminescence spectroscopy (PL). The structures with different core shapes and controllable shell thickness exhibited unique optical properties. It is found that the nanoscale Ag@CeO 2 core–shell photocatalysts exhibit significantly enhanced photocatalytic activities in the O 2 evolution and MB dye degradation compared to pure CeO 2 nanoparticals. The enhancement in photocatalytic activities can be ascribed to the localized surface plasmon resonance (SPR) of Ag cores. Moreover, larger active interfacial areas and contact between metal/semiconductor in the core–shell structure facilitate transfer of charge carriers and prolong lifetime of photogenerated electron-hole pairs. It is expected that the Ag@CeO 2 core–shell structure may have great potential in a wider range of light-harvesting applications.