Hierarchically mesoporous/macroporous structured TiO2 for dye-sensitized solar cells

Abstract

In this study, hierarchical TiO₂ with macro- and mesostructure is prepared and applied in dye-sensitized solar cell (DSSCs). To achieve the hierarchical structure, hard and soft templating is combined. Polystyrene spheres serve as the hard template for μm-scale macropores, and triblock copolymers act as the soft template of nm-scale mesopores. The prepared hierarchical TiO₂ is analyzed by TEM, XRD and N₂ sorption, and results indicate that meso/macroporous structure is successfully obtained. Mesoporous structure provides a larger surface area for dye adsorption, and macroporous structure induces a faster electron transportation property. Combining the advantages of mesopores and macropores, the prepared hierarchical TiO₂ DSSCs show a higher photon to electron efficiency in comparison to individual mesoporous and macroporous samples.