Syntheses and Characterizations of Carbides and Lithiated Oxides of Group V and VI Metals

• Main Authors: Chun-Hsiung Chien, 簡俊雄
• Other Authors: Hsin-Tien Chiu
• Format: Others
• Language: en_US
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/40538669594297737345

博士 === 國立交通大學 === 應用化學系所 === 95 === The carbides and lithilated oxides of group V and VI metals were synthesized by means of homogenous solution-phase reaction and gas-solid reaction. In the solution-phase reaction, we explored three methods for the syntheses of LiTaO3, LiNbO3, LiMoO2 and Mo2C. Nanosized LiTaO3 (50 – 100 nm) and LiNbO3 (20 – 50 nm) powders can be obtained in liquid-phase reaction by heating the precursors generated between MCl5 (M = Ta, Nb) and alkyllithiums in THF. LiMoO2 powders were synthesized from a precursor prepared by reacting EtLi and MoOCl3(THF)2 in the air for a week. Molybdenum carbide particles were prepared via carbothermal reduction of the precursors obtained from the reaction between MoOCl3(THF)2 and nBuLi in the presence of THF. In the gas-solid reaction, we selected three compounds, 1-chlorobutane, hexachlorobenzene and carbon tetrachloride, as gas presursors for the reaction with Mo powders. Mo2C@a-C core-shell powders have been synthesized from the reactions between Mo metal powders with 1-chlorobutane or with hexachlorobenzene at 1173 K. Carbon hollow spheres (1 – 3 μm) and particles (200 – 300 nm) have been synthesized from CCl4 and Mo at 873 K - 1173 K.