Fabrication of a Pt film with a well-defined hierarchical pore system via “solvent-evaporation-mediated direct physical casting”

We fabricated a well-ordered Pt thin film with a bimodal pore system by combining the modified liquid crystal templating method (solvent-evaporation-mediated direct physical casting, SEDPC) with colloidal crystal templating. The direct observation of the film by high-resolution scanning microscopy (HR-SEM) showed the formation of a hierarchical porous structure. The resulting Pt film possesses macropores (ca. 460 nm), interconnected windows (ca. 100 nm), and mesopores (ca. 3–4 nm). Macropore wall consists of small nanoparticles of ca. 3 nm in size. These nanoparticles are interconnected to create mesoporosity. The cyclic voltammogram of the resulting Pt film in sulfuric acid revealed a typical feature which can identify the clean Pt surface.