Characterization of Titanium Nitride Nanotubes

TiNTs were prepared by a classical hydrothermal method and characterized as described previously.^{22 (link)} TiNTs powder was appropriately suspended in pure water (0.1 mg mL⁻¹), then ultrasonicated for 5 min. A sample of 20 μL was observed using a transmission electron microscope (TEM, Tecnai G2, FEI, Netherlands) at 200 kV and images were acquired with a Veleta camera (Olympus, Japan). TiNTs powder was also characterized by SEM using a ZEISS Sigma scanning electron microscope (SEM) with a 10 kV accelerating voltage. For crystallinity, X-ray diffraction (XRD) was performed at room temperature with an X-ray diffractometer (X′ Pert PRO MPD, PANalytical Co., Holland). Monochromatic Cu Kα-radiation (λ = 1.5418 Å) was obtained with Ni-filtration and a system of diverging and receiving slides of 0.5° and 0.1 mm, respectively. The diffraction pattern was measured at a voltage of 40 kV and a current of 30 mA over a 2θ range of 3–40° using a step size of 0.02° at a scan speed of 1 s per step.