Tungsten oxide （W18O49） 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 W18049 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 be- low the vacuum level. The feasibility of using the such-fabricated nanorods as field emitters was tested and the related mecha- nism was also discussed.
