Heterogeneous Seeded Growth of Chiral Au Nanostructures on PbS Nanocrystals

Chiral plasmonic nanoparticles have been widely prepared through the seed-mediated overgrowth. However, the synthesis of chiral plasmonic-based hetero-nanostructures with multiple components via heterogeneous nucleation and growth has posed significant challenges. In this work, we develop a novel approach for the synthesis of chiral Au/PbS nano-heterostructures. This approach utilizes PbS nano-octahedrons as seeds and chiral cysteine-phenylalanine as symmetry-breaking agents to enable the selective growth of chiral Au on the single vertex of PbS nano-octahedrons. The optical properties of the resulting composites can be tuned by independently controlling synthetic parameters, such as the handedness and concentration of enantiomers and Au precursor. The chiral composites coupling PbS with plasmonic nanoparticles exhibit enhanced photoelectric performance compared with the corresponding achiral counterparts as a result of the difference in extinction and interface contacts between Au and PbS. This study provides a rational design for the construction of functional chiral nanostructures, not only expanding their application in various fields, such as chiral catalysis, spin devices, and chiral sensing, but also triggering new or enhanced properties by the integration of chiral plasmonic effect with other functional features.