Just Justus, Coughlan Claudia, Singh Shalini, Ren Huan, Müller Oliver, Becker Pascal, Unold Thomas, Ryan Kevin M
MAX IV Laboratory, Lund University, Fotongatan 2, 22484 Lund, Sweden.
Department of Chemical Sciences and Bernal Institute, University of Limerick, V94T9PX Limerick, Ireland.
ACS Nano. 2021 Apr 27;15(4):6439-6447. doi: 10.1021/acsnano.0c08617. Epub 2021 Mar 26.
Copper chalcogenide nanocrystals find applications in photovoltaic inks, bio labels, and thermoelectric materials. We reveal insights in the nucleation and growth during synthesis of anisotropic CuZnSnS nanocrystals by simultaneously performing in situ X-ray absorption spectroscopy (XAS) and small-angle X-ray scattering (SAXS). Real-time XAFS reveals that upon thiol injection into the reaction flask, a key copper thiolate intermediate species is formed within fractions of seconds, which decomposes further within a narrow temperature and time window to form copper sulfide nanocrystals. These nanocrystals convert into CuZnSnS nanorods by sequentially incorporating Sn and Zn. Real-time SAXS and ex situ TEM of aliquots corroborate these findings. Our work demonstrates how combined in situ X-ray absorption and small-angle X-ray scattering enables the understanding of mechanistic pathways in colloidal nanocrystal formation.
硫属铜化物纳米晶体在光伏油墨、生物标记和热电材料中有着应用。我们通过同时进行原位X射线吸收光谱（XAS）和小角X射线散射（SAXS），揭示了各向异性CuZnSnS纳米晶体合成过程中的成核和生长情况。实时XAFS表明，将硫醇注入反应烧瓶后，在几秒钟内就会形成一种关键的硫醇铜中间物种，该物种在狭窄的温度和时间窗口内进一步分解，形成硫化铜纳米晶体。这些纳米晶体通过依次掺入Sn和Zn转化为CuZnSnS纳米棒。等分试样的实时SAXS和非原位TEM证实了这些发现。我们的工作展示了原位X射线吸收和小角X射线散射相结合如何能够理解胶体纳米晶体形成的机理途径。
