The preferential growth of ZnS on ZnOnanorods

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 View the MathML source{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.