US 11,732,186 B2
Core/shell nanocrystals with copper sulfide cores and lead sulfide shells
Janice E. Boercker, Fairfax, VA (US); Sarah F. Brittman, Washington, DC (US); Joseph G. Tischler, Alexandria, VA (US); Patrick Y. Yee, Washington, DC (US); Chase T. Ellis, Silver Spring, MD (US); Paul D. Cunningham, Baltimore, MD (US); Rhonda M. Stroud, Washington, DC (US); Michael H. Stewart, Springfield, VA (US); and Steven C. Erwin, Alexandria, VA (US)
Assigned to The Government of the United States of America, as represented by the Secretary of the Navy, Arlington, VA (US)
Filed by The Government of the United States of America, as represented by the Secretary of the Navy, Arlington, VA (US)
Filed on Apr. 23, 2021, as Appl. No. 17/238,265.
Claims priority of provisional application 63/014,801, filed on Apr. 24, 2020.
Prior Publication US 2021/0332291 A1, Oct. 28, 2021
Int. Cl. C09K 11/56 (2006.01); C09K 11/58 (2006.01); C09K 11/66 (2006.01); B82Y 40/00 (2011.01); B82Y 20/00 (2011.01)
CPC C09K 11/56 (2013.01) [C09K 11/582 (2013.01); C09K 11/661 (2013.01); B82Y 20/00 (2013.01); B82Y 40/00 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A process for synthesizing core/shell nanocrystals, wherein each of the core/shell nanocrystals includes a respective copper sulfide core and a respective lead sulfide shell, the process comprising:
mixing an amount of Pb-oleate with 1-octadecene reaction flask within an N2 glovebox to form a Pb-oleate mixture;
removing the flask from the glovebox and heating the Pb-oleate mixture under an argon atmosphere to 60° C.;
while maintaining the temperature of the Pb-oleate mixture at 60° C., adding an amount of copper sulfide core hexane solution and an amount of bis(trimethylsilyl)sulfide stock solution to the Pb-oleate mixture to form a reaction mixture, the amount of Pb-oleate and the amount of bis(trimethylsilyl)sulfide stock solution being maintained at a Pb-oleate:bis(trimethylsilyl)sulfide molar ratio of 1.5:1;
rapidly stirring the reaction mixture for 6 minutes to form the core/shell nanocrystals from the reaction mixture, wherein each the core/shell nanocrystals includes the respective copper sulfide core and the respective lead sulfide shell;
cooling the flask to room temperature;
returning the flask to the N2 glovebox and adding toluene and acetonitrile to the flask in the N2 glovebox;
removing the reaction mixture from the flask and placing it in a centrifuge tube; and
centrifuging the reaction mixture to precipitate and remove the core/shell nanocrystals from the reaction mixture;
wherein the amount of Pb-oleate and the amount of bis(trimethylsilyl)sulfide stock solution are configured to produce number of lead sulfide monolayers on each of the copper sulfide cores.