Revealing 3D Information of Porous Catalytic Structures Prepared by Template Methods

Nanostructures of diverse materials prepared by using monodispersed colloidal spheres as templates have found potential applications in many fields such as photonic crystals, sensors, and catalysts. Such nanostructured materials include polymers, oxides, metals, semiconductor compounds, as well as composites. Polystyrene (PS) beads are commonly used as the templates since the removal of the templates can be achieved by both calcination and dissolution [1,2]. Templates fabricated from a colloidal PS solution consist of many close-packed regions, where 26% void space can be used for filling up with functional materials [2]. After the removal of the PS spheres, the remaining nanostructures have high surface area and 74% spherical void volume, which allow efficient mass transport and further materials modification. These templated nanostructures incorporated with catalytic nanoparticles (NPs) attract a wide range of research interests, due to their potential in reducing and tuning the loading of precious catalytic metals, improving catalytic performance, as well as the scalability for mass production.