[13p-D305-1~16] 9.2 Nanoparticles, Nanowires and Nanosheets

▲ [13p-D305-1] Preparation of Molybdenum Trioxide Nano-Needles from Molybdenum Oxide Porous Wire by The Pulsed Wire Discharge

〇(D)Ngo Minh Chu¹, Nguyen Duy Hieu¹, Thi Mai Dung Do¹, Tadachika Nakayama¹, Koichi Niihara¹, Hisayuki Suematsu¹ (1.Extreme Energy-Density Research Institute, Nagaoka University of Technology)

Keywords:Molybdenum oxide, nano-needles, pulsed wire discharge

Molybdenum trioxide (MoO₃) exhibits electrochromic, photochromic, thermochromic, and gasochromic effects. Among many morphologies of nano metal and metal oxides, the nanorods (needle structure) are pointed in some literature to be the most promising morphology for electrochemical, optical, and catalytic applications. In this research, from a wire with a surface of the porous MoO₃ structure and the core of Mo metal, the nano-needle structure of MoO₃ has been synthesized by pulsed wire discharge (PWD) method. After evaporating a wire with a charged voltage of 6 kV under 25 kPa of oxygen partial pressure and 25 kPa of additional Ar gas, different structures of MoO₃ such as needles, spheres were formed. The XRD result showed the existence of MoO₃ alpha and beta phases in the sample. From FE-SEM images, the high density of the nano-needle structure of MoO₃ with a diameter under 100 nm was observed. It is very rare in the PWD method because after evaporating, the metal and metal oxides vapor are formed and tend to become spherical particles. By using FE-TEM, the beta-MoO₃ needle structure was confirmed by EDX and lattice image analysis.
The nano-needle structure of MoO₃ was synthesized by a new method of PWD from a wire with a surface of the porous MoO₃ structure and core of Mo metal.