文摘
CuInS2 nanocrystals are prepared by ion exchange with template Cu2鈥?i>xS nanoplatelets and InX3 [X = chloride, iodide, acetate (OAc), or acetylacetonate (acac)]. The morphologies of the resultant nanocrystals depend on the InX3 precursor and the reaction temperature. Exchange with InCl3 at 150 掳C produces CuInS2 nanoplatelets having central holes and thickness variations, whereas the exchange at 200 掳C produces intact CuInS2 nanoplatelets in which the initial morphology is preserved. Exchange with InI3 at 150 掳C produces CuInS2 nanoplatelets in which the central hollowing is more extreme, whereas exchange with In(OAc)3 or In(acac)3 at 150 掳C produces intact CuInS2 nanoplatelets. The results establish that the ion exchange occurs through the thin nanoplatelet edge facets. The hollowing and hole formation are due to a nanoscale Kirkendall Effect operating in the reaction-limited regime for displacement of X鈥?/sup> at the edges, to allow insertion of In3+ into the template nanoplatelets.