Gas-phase synthesis of nitrogen-doped Ti O 2 nanorods by microwave plasma torch at atmospheric pressure

Nitrogen (N)-doped titanium dioxide ( Ti O 2 ) nanorods were directly synthesized via decomposition of gas-phase titanium tetrachloride ( Ti Cl 4 ) by an atmospheric microwave plasma torch. X-ray diffraction, field-emission scanning electron microscope, field-emission transmission electron microscope, and electron-energy-loss spectroscopy (EELS) have been employed to investigate fraction of the anatase and rutile phases, diameter and length, and chemical composition of the nanorods, respectively. The diameters of the nanorods are approximately 30–80 nm and the length is several micrometers. EELS data show that incorporation of N into the O site of Ti O 2 nanorods was enhanced in N 2 gas by the microwave plasma torch. Also, a growth model of the rods was proposed on the basis of vapor-liquid-solid mechanism.