کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1329987 | 1500117 | 2013 | 7 صفحه PDF | دانلود رایگان |
Transmission and scanning electron microscopy are used to examine the sulphidation of hydrothermally grown [0001]-oriented ZnO nanorods in aqueous thioacetamide (CH3C(S)NH2) solution. At the early stages of growth, the reaction occurs preferentially on the (0001) top surface, confirmed to be Zn-polar by convergent beam electron diffraction, and on the lines of intersection of the {101¯0} facets. It is shown that the reaction involves surface migration of Zn species towards ZnS deposits. The presence of voids at the ZnS/ZnO interface also confirms a Kirkendall mechanism where ZnS grows from the top surface of the deposit.
TEM image comparison of ZnS surface decoration on ZnO nanorod (a)after 15 min sulphidation shows a relatively uniform deposit on the (0001) end facet, (b) 30 min sulphidation shows a more extensive reaction on the (0001) facet which gives a mushroom-like appearance of the nanorod and (c) 60 min sulphidation shows the end cap partially detached and a voided region underneath. The presumed growth direction is arrowed (based on the lack of reaction at the other end). Figure optionsDownload as PowerPoint slideHighlights
► The mechanism of sulphide growth on (0001) ZnO nanorods is examined by TEM and SEM.
► The reaction occurs on (0001) and on the lines of intersection of the {101¯0}.
► The reaction involves Zn migration to reaction sites via surface diffusion.
► A voided interlayer between ZnS and ZnO may be explained by the Kirkendall effect.
Journal: Journal of Solid State Chemistry - Volume 199, March 2013, Pages 109–115