SiO2/Ta2O5 Core-Shell Nanowires and Nanotubes

Tantalizing silica: SiO2/Ta2O5 core–shell nanostructures were formed by reducing SiO2 nanowires under a Ta atmosphere at 950 °C. The diameter of the SiO2 nanowires inside the core–shell nanostructures could be manipulated by modifying the reduction time. Treatment of the core–shell structures in dilute HF solution yielded Ta2O5 nanotubes (see TEM image), whereas Ta2O5 nanowires were formed directly by increasing the reduction time.