Growth of single-crystal W whiskers during humid H2/N2 reduction of Ni, Fe–Ni, and Co–Ni doped tungsten oxide
Growth of single-crystal W whiskers during humid H2/N2 reduction of Ni, Fe–Ni, and Co–Ni doped tungsten oxide
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DOI：
10.1016/j.jallcom.2009.02.126
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发表时间：
2009-08
影响因子：
6.2
通讯作者：
Shiliang Wang;Yuehui He;J. Zou;Yong Wang;Han Huang
中科院分区：
文献类型：
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作者：
Shiliang Wang;Yuehui He;J. Zou;Yong Wang;Han Huang
通过在潮湿的h2和N2混合气氛中还原Ni、Ni - fe和Ni - co掺杂的氧化钨，获得了大量的W晶须。采用XRD和SEM对还原产物的物相和形貌进行了表征。TEM和EDS分析表明，晶须为W单晶，生长尖端有典型的合金颗粒（Ni-W、Fe-Ni或Co-Ni-W）。推测形成的W晶须是由合金颗粒诱导形成的。我们的实验结果表明，在氧化钨还原过程中，预还原的Ni、Fe-Ni或Co-Ni颗粒不仅作为W氧化物W相初始生长的助核剂，而且在气态WO2(OH)2的还原分解过程中起到催化剂的作用。
Numbers of W whiskers were obtained by reducing Ni, Ni–Fe, and Ni–Co doped tungsten oxide in a mixed atmosphere of humid H2and N2. The phases and morphologies of the reduction products were characterized by XRD and SEM. Intensive TEM and EDS analyses showed that the obtained whiskers were W single crystals which typical have alloyed particles (Ni–W, Fe–Ni, or Co–Ni–W) at the growth tips. The formed W whiskers were presumed to be induced by the alloyed particles. Our experimental results revealed that, during the reduction process of tungsten oxide, the pre-reduced Ni, Fe–Ni, or Co–Ni particles not only served as nucleation aids for the initial growth of W phase from W oxide but also played the roles of catalysts during the reductive decomposition of gaseous WO2(OH)2.