How Can We Efficiently Fabricate Nanostructured Materials with Unprecedented Properties?

INTRODUCTION Decades of research have been devoted to studying the properties of nanostructured materials-e.g.,single crystalline wires,porous materials,polycrystals and laminatesfor applications ranging from heterogeneous catalysts to highstrength structures.1 Interest in nanoscale materials is motivated by their new(and often enhanced)properties,which are attributed to large interfacial areas and high surface defect concentrations.2 Nanoscale catalysts exhibit superior activities due to surface strains,increased population of dangling bonds,and unique surface electronic states established by surface/subsurface atomic interactions.3,4 For instance,bulk Au surfaces are relatively inert but Au nanoparticles exhibit excellent catalytic behavior.1,3 In a similar fashion,nanocrystalline metals possess exceptionally high yield strengths due to an increased barrier for plasticity mechanisms to operate in confined volumes and in close proximity to interfaces.1,2,5 Unfortunately,fabrication techniques for these materials are frequently resource-intensive and cannot be translated into commercial-scale processing.