Ethylenediamine and ethylene glycol stabilized colloidal PbX (X=S, Se, Te) nanocrystals via amide- and ester-derivatives of 1-(propanoic acid)-3-methylimidazolium bromide ionic liquid

摘要

The stability of colloidal nanocrystals in common solvents such as water is paramount in the processibility and practical application of these materials in industrial scale. Herein, we show that a bifunctional ionic liquid (IL) 1-(propanoic acid)-3-methylimidazolium bromide is an effective capping agent in the solvothermal synthesis of water-stable colloidal lead chalcogenide, PbX (X=S, Se, Te), nanocrystals. IL-capped PbX were produced using ethylenediamine (ED) and ethylene glycol (EG) as solvents. The addition of EG or ED in water at 50% (v/v) produced higher quality nanocrystals compared with nanocrystals produced in pure water, EG or ED. This enhancement originated from direct stabilization from the in situ formation of amide- and ester-derivatives of the IL in aqueous ED and EG, respectively.