We demonstrate the colloidal synthesis of single-crystalline Al nanocubes by decomposing AlH3 with Tebbe’s reagent in tetrahydrofuran. The size and shape of the Al nanocubes is controlled by the reaction time and the ratio of AlH3 to Tebbe’s reagent, which together with reaction temperature, establish kinetic control over Al nanocube growth. Electron paramagnetic resonance spectroscopy indicates Tebbe’s reagent is reduced by AlH3, generating Ti3+Cp2μ2H2AlH-THF, the active catalyst for the reduction of AlH3 by hydride oxidation. We suspect formation of an Al-C bond between AlH3 and the cyclopentadienyl ring of Ti3+Cp2μ2H2AlH -THF is essential to the growth of Al nanocubes. The reaction proceeds through the formation of cubic superlattices composed of uniform Al clusters that grow into Al nanocubes provided a sufficient excess of AlH3. Theoretical calculations reveal that Al nanocubes have extremely high localized electric fields at their corners and have an optical response that is incredibly sensitive to coupling with metallic substrates. Chemically synthesized Al nanocubes are cost-effective Earth-abundant alternatives to noble metal nanoparticles for plasmonics and nanophotonics.

Aluminum nanocubes have sharp corners

2019 Fall National Meeting

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