Center for Materials Crystallography, Department of Chemistry and iNANO, Aarhus University , Langelandsgade 140, DK-8000 Aarhus C, Denmark.
ACS Nano. 2014 May 27;8(5):4295-303. doi: 10.1021/nn5010638. Epub 2014 Apr 17.
The formation, growth, and phase transition of colloidal monodisperse spherical copper sulfide nanocrystals synthesized in dodecanethiol have been followed by in situ synchrotron powder X-ray diffraction (PXRD). The formation of nanocrystals involves a thermal decomposition of the crystalline precursor [CuSC12H25], which upon heating forms an isotropic liquid that subsequently turns into colloidal β-chalcocite phase Cu2S nanocrystals. The redox reaction step in the precursor solution has been studied by proton NMR. Upon heating, high digenite phase nanocrystals are formed through a solid-state rearrangement phase transition of the β-chalcocite phase nanocrystals at temperatures above 260 °C. TEM and PXRD reveal that the nanocrystal size is independent of synthesis temperature and stabilizes after the phase transition has completed. Spherical monodisperse nanocrystals are obtained in all experiments, with the nanocrystals in the β-chalcocite phase (7 nm) being smaller than those in high digenite phase (11 nm).
采用同步辐射粉末 X 射线衍射（PXRD）原位跟踪研究了在十二硫醇中合成的胶体单分散球形硫化铜纳米晶体的形成、生长和相转变。纳米晶体的形成涉及到晶体前体[CuSC12H25]的热分解，加热时形成各向同性液体，随后转化为胶体β-辉铜矿相 Cu2S 纳米晶体。通过质子 NMR 研究了前驱体溶液中的氧化还原反应步骤。加热时，β-辉铜矿相纳米晶体在 260°C 以上的温度下通过固态重排相转变形成高铜蓝矿相纳米晶体。TEM 和 PXRD 表明，纳米晶尺寸与合成温度无关，并且在相转变完成后稳定。在所有实验中都得到了球形单分散纳米晶体，β-辉铜矿相（7nm）的纳米晶体小于高铜蓝矿相（11nm）的纳米晶体。
