Research

Shape-Controlled Synthesis of Nanomaterial Building Blocks

The role of nanoparticle shape can be as important as crystal chemistry in determining the electronic and catalytic properties of inorganic clusters and nanoparticles. Yet the chemistry governing shape at this level is not well understood, especially in binary and ternary materials. We are using a combination of theory and high-throughput experimental techniques to discover a common origin of shape in different nanomaterials systems, with special attention on classes of materials useful for energy generation/storage and catalysis.

A photo of Au nanoclusters in microwells (Left); an SEM of polyhedral Ag nanoparticles (Right)

A photo of Au nanoclusters in microwells (Left); an SEM of polyhedral Ag nanoparticles (Right)

Bottom-up Assembly of Artificial Solids

Nanocrystals are building blocks for a new class of functional, composite materials that can be completely assembled from the bottom up. Over the years many synthetic methods have been developed to generate particles with exquisite control of shape and size in metal, dielectric and semiconducting materials. Our focus is on arranging these building blocks into precisely ordered lattices, where they become the component "atoms" of new, functional materials with unusual physical and chemical properties that cannot be found in nature. We are interested in both the fundamental science of self-assembly, and diverse applications including optical metamaterials and plasmon-enhanced catalysis.

SEM images of an assembled colloidal superlattice with space group I43d   (Left; Center). The superlattice forms spontaneously in Monte Carlo simulations of Ag octahedral particles with depletion attractions (Right).

SEM images of an assembled colloidal superlattice with space group I43d   (Left; Center). The superlattice forms spontaneously in Monte Carlo simulations of Ag octahedral particles with depletion attractions (Right).