Near-infrared plasmonic binary copper-based chalcogenides have found promising applications in photovoltaics and photothermal therapy. Here, we report a facile synthetic protocol for aqueous soluble covellite (CuS) nanocrystals (NCs) at room temperature. In contrast to previously reported routes, the present method involves the reaction of Cu precursors (e.g. CuCl₂, Cu(NO₃)₂, Cu(Ac)₂) with sulphur precursors (e.g. Na₂S and (NH₄)₂S) under ambient conditions in the presence of various ligands, requiring neither high temperature and high pressure nor an inert atmosphere. The as-synthesized CuS NCs, without any further ligand exchange, can be readily dispersed in water and exhibit well-defined near-infrared (NIR) plasmon absorbance. The scalability and reproducibility of the present procedure allow for the gram-scale production of CuS NCs in a one-pot reaction, which is elaborated by upscaling the amounts of precursors and solvents/ligands. In particular, when excited with an 806 nm laser (1.2 W cm⁻²), the aqueous soluble covellite NCs produce significant photothermal heating with a photothermal transduction efficiency of 20.3%, comparable to previously reported binary copper chalcogenides. Combined with good photothermal transduction properties, photostability and synthesis scalability, the present work provides a general and cost-effective synthetic protocol for not only Cu_2−xS but also other copper chalcogenides for promising photothermal applications.

中文翻译：

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高光热转化率室温合成水溶性可溶珍珠铜CuS纳米晶体†

近红外等离子体等离子体二元铜基硫族化物已在光伏和光热疗法中找到了有前途的应用。在这里，我们报告在室温下水溶性水溶velvellite（CuS）纳米晶体（NCs）的简便的合成协议。与先前报道的路线相反，本方法涉及Cu前体（例如CuCl ₂，Cu（NO ₃）₂，Cu（Ac）₂）与硫前体（例如Na ₂ S和（NH ₄）_{2）的反应。}S）在环境条件下，在各种配体存在下，既不需要高温高压，也不需要惰性气氛。合成后的CuS NCs无需任何进一步的配体交换，就可以很容易地分散在水中，并显示出明确的近红外（NIR）等离子体激元吸收率。本方法的可扩展性和重现性允许在一锅反应中以克规模生产CuS NC，这可通过扩大前体和溶剂/配体的量来完善。特别是当被806 nm激光（1.2 W cm ^-2），水溶性可溶的velvellite NCs产生显着的光热加热，其光热转换效率为20.3％，与先前报道的二元硫属铜化物相当。结合良好的光热传导特性，光稳定性和合成可扩展性，本工作不仅为Cu _{2- x} S还为希望的光热应用提供了其他铜硫族化物，提供了一种通用且具有成本效益的合成方案。