A robust method for the synthesis of colloidal PbS nanosheets

In the synthesis of colloidal PbS nanosheets, acetic acid either injected externally or produced during the reaction has a significant effect on the growth of the nanosheets. When the acetic acid to lead molar ratio is above 1 : 8, no nanosheets are observed in the product. By replacing lead acetate with lead oxide to prepare the lead precursor for the reaction, the effect of acetic acid is avoided, resulting in a robust synthesis with nearly 100% success rate. In the new synthesis, the purity of trioctylphosphine (the co-solvent for sulfur precursor) has no significant effect on the formation of nanosheets. Thickness tunability is achieved in the acetate-free synthesis by tuning the reaction temperature.(C) 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim