Surfactant-assisted hydrothermal growth of single-crystalline ultrahigh-asgect-ratio vanadium oxide nanobelts

Single-crystalline vanadium oxide nanobelts were obtained through a surfactant-directed growth process under hydrothermal conditions using V ₂O₅ as a precursor. The shape and size were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), ultraviolet/ visible (UV/vis) spectroscopy, X-ray photoelecton spectroscopy (XPS), high-resolution TEM (HRTEM), and selected area electron diffraction (SAED) were used to characterize the composition and structure of the as-prepared nanobelts. The as-obtained vanadium oxide nanobelts are up to several hundreds of micrometers in length, 100-200 nm in diameter, and 20-30 nm in thickness. A possible mechanism was proposed to account for the formation of the nanobelts. The influence of the concentration of reactants, the reaction time, the concentration of the surfactant, and the reaction temperature on the morphology of the resulting products are discussed in detail. Furthermore, we tested the electrochemical intercalation properties with Li⁺ of the postannealing sample by calcining the obtained vanadium oxide nanobelts at 400°C. It was found that the morphology and the structure of the synthesized product had an important influence on the electrochemical intercalation properties.