Anisotropic materials can exhibit unique catalytic, optoelectronic, and thermal properties due to their broken structural symmetry. The synthesis of nanoscale anisotropic structures is particularly challenging. Typical synthetic approaches start with seed particles and then exploit ligands to mediate the direction and rate of subsequent crystal growth. Unfortunately, this strategy often yields a poor selectivity (<i>e.g.</i> low yield) for the desired anisotropic phase, either because bulk nucleation dominates and leads to isotropic growth or because inhomogeneous ligand coverage on the seed particles leads to irregular growth. It is necessary to control these and other steps of the synthesis to ensure rational design of unique and functional materials. Here we present a strategy for self-limited, non-seeded growth of anisotropic nanoparticles that involves prescribed structural symmetry breaking. We prepare AgBr nanoparticles and show that these transform, under UV irradiation in the presence of a reductant, into anisotropic nanoscale dimers composed of a Ag metal nanoparticle fused to the parent AgBr phase. The dimers are formed at &gt; 90% yield and their metal and metal-halide phases are separated by an epitaxially sharp interface. We investigate the plasmonic and catalytic properties of these and related architectures, and foresee this work informing the preparation of nanostructures with higher structural and functional complexity.

Synthesis of anisotropic nanostructures through controlled symmetry breaking

255th National Meeting (2018)

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