Tungsten oxide(W 18 O 49) nanorods were grown by directly heating tungsten foils covered with potassium bromide(KBr) in low-pressure wet oxygen.The approach featured such advantages as convenient manipulation,low cost and rapid accessibility to high temperatures.A solid-liquid-solid(SLS) mechanism is believed to have dominated the growth process,in which the W 18 O 49 nanorods segregated from eutectic droplets of potassium tungstate and tungsten oxide.The ultraviolet photoelectron spectroscopy(UPS) analysis disclosed that the valence band maximum(VBM) of these nanorods was approximately 9 eV below the vacuum level.The feasibility of using the such-fabricated nanorods as field emitters was tested and the related mechanism was also discussed.
