Microstructural characterization of single-crystalline potassium hollandite nanowires

Single-crystalline potassium hollandite KTi8O16.5 nanowires were synthesized by the molten salt method at 800 °C. Scanning electron microscopy observation shows that the nanowires are with octagonal cross-sections, and combined analyses of transmission electron microscopy and the electron diffraction results show that the terminated planes are angled 90 or 60 degrees to the growth direction, [001] crystallography direction. Ordering of the potassium cations in the tunnels was revealed by electron diffraction. The mechanism of one-dimensional growth of the nanowires was attributed to the oriented attachment mechanism.