H.J.FAN
,
M.Zacharias
材料科学技术（英）
Vapor-phase growth of ZnO nanowires based on gold catalyst is usually accompanied with lateral crawling growth on the substrate surface. We present results from our systematic experiments where the growth temperature and catalyst size are controlled. The data corroborate that it is possible to obtain clean vertical nanowire arrays while avoiding the crawling growth. On the other hand, crawling growth can be manipulated to obtain root-interconnected nanowire arrays, which could be useful for certain applications. Our results also imply that the previously suggested growth mechanism for the wire-on-wall hybridstructure might be incorrect. Finally, we show the formation of sub-millimeter long, straight ZnO nanowalls by combining a gold-catalyzed epitaxial growth of vertical nanowires and their mergence due to a confined crawling growth. These unconventional nanostructures might have unique electric or optical transport properties.
关键词:
Nanowire
,
nanowall
,
ZnO
,
crawling
,
growth
陈立峰
,
宋卫林
,
张亚红
,
杨为民
,
吴良华
,
唐颐
催化学报
doi:10.1016/S1872-2067(14)60135-2
以共沉淀法所制的工业铁硅球体催化剂(indus-FS)为原料,用改进的有机胺蒸气相传输转化法,得到了负载高分散铁的交织氧化硅纳米线球体催化剂(NW-FS),并用于费托合成反应.在所制纳米线催化剂中,原料催化剂中氧化硅在氧化铁诱导下成功地转变成纳米线交织微球载体,而氧化铁组分则高度分散在氧化硅纳米线上.用扫描电镜、透射电镜、X射线衍射、低温氮吸附、X射线光电子能谱和程序升温还原等方法对所得纳米线催化剂进行了表征.在费托合成中,纳米线铁硅催化剂由于其特殊的堆积结构所导致的低的扩散阻力和高的铁活性组分分散度,提高了低碳烯烃尤其是乙烯的选择性.纳米线铁硅催化剂上低碳产物(C2-C4)的烯烷比为3.3,高于母体工业催化剂的1.9.
关键词:
纳米线
,
纳米金属催化剂
,
费托合成
,
煤化工
,
二次反应
