Hybrid nanocrystals (HNCs) which include multiple nano-composites attract great interest owing to their structural uniqueness and combined properties. The unique morphology of HNCs provides the opportunity to undergo structural transformation into new controlled morphology. For the first time, we present the detailed pressure processing of HNCs superlattices (HNC-SLs) self-assembled from quantum-dot-Au (QD-Au) HNCs. By simultaneously measuring <i>in situ</i> synchrotron-based small/wide angle X-ray scattering (SAXS/WAXS), structural transformation of QD-Au HNCs at both atomic and SL level were revealed. <i>In situ</i> SAXS and WAXS showed that during pressure processing both atomic and SL underwent permanent structural transformation. The migration and coalescence of Au NCs were observed on the QDs’ surface during the pressure-processing. Due to the deviatoric stress along different SL axes, two different unique hetero-structures, hetero-dimers and hetero-rods were obtained. Mechanistic studies showed an interesting pressure-induced ‘two-step’ structural transformation process. These results suggest that HNCs can be converted into novel hetero-structures under high pressure, which serves as a unique technique for fabrications of novel hetero-nanostructures that are difficulty to achieve through conventional synthesis methods.

Pressure-induced hetero-dimer and hetero-rods formation through intraparticle coalescence of QD-Au satellite nanocrystals

254th National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.