Houtepen Arjan J, Koole Rolf, Vanmaekelbergh Daniël, Meeldijk Johannes, Hickey Stephen G
Condensed Matter and Interfaces, University Utrecht, POB 80000, 3508 TA Utrecht, The Netherlands.
J Am Chem Soc. 2006 May 31;128(21):6792-3. doi: 10.1021/ja061644v.
Monodisperse spherical, star-shaped, and octahedral PbSe nanocrystals were synthesized via a hot injection method. We show that the shape and size of the colloidal PbSe nanocrystals are determined by the concentration of acetate and that only acetate-free reaction mixtures result in spherical nanocrystals. The presence of acetate leads to efficient oriented attachment of smaller PbSe nanoparticles along the 100 crystal axis. Comparing different synthesis procedures from the recent literature with our observations, we propose that the acetate, naturally present in insufficiently dried reaction mixtures, is responsible for many of the PbSe crystal shapes reported in the literature. In addition we show that it is possible to synthesize these star-shaped nanocrystals so monodisperse that they form ordered monolayers with crystal alignment.
通过热注射法合成了单分散的球形、星形和八面体 PbSe 纳米晶体。我们表明，胶体 PbSe 纳米晶体的形状和尺寸由醋酸盐的浓度决定，只有无醋酸盐的反应混合物才能产生球形纳米晶体。醋酸盐的存在导致较小的 PbSe 纳米颗粒沿 100 晶轴有效定向附着。将近期文献中的不同合成方法与我们的观察结果进行比较，我们认为，未充分干燥的反应混合物中天然存在的醋酸盐是文献中报道的许多 PbSe 晶体形状的原因。此外，我们还表明，可以合成如此单分散的星形纳米晶体，以至于它们形成具有晶体排列的有序单层。
