Ta2O5Nanowires: a novel synthetic method and their solar energy utilization

Abstract

Single-crystalline uniform Ta₂O₅ nanowires are prepared by a novel synthetic route. The formation of the nanowires involves an oriented attachment process caused by the reduction of surface energy. The nanowires are successfully applied to photocatalytic H₂ evolution, contaminant degradation, and dye-sensitized solar cells (DSCs). The Ta₂O₅-based DSCs reveal a significant photovoltaic response, which has not been reported. As a photocatalyst, the Ta₂O₅ nanowires possess high H₂ evolution efficiency under Xe lamp irradiation, nearly 27-fold higher than the commercial powders. A better performance of photocatalytic contaminant degradation is also observed. Such improvements are ascribed to better charge transport ability for the single-crystalline wire and a higher potential energy of the conduction band. This new synthetic approach using a water-soluble precursor provides a versatile way to prepare nanostructured metal oxides.