When the size and the shape of materials are reduced to the nanoscale dimension, their physical and chemical properties can change dramatically. This book demonstrates the controlled size and shape of nanostructured materials and their applications. The applications cover photocatalysts, biomedicals, nanomaterials, fuel cells and supercapacitors, lithium-ion batteries, light-emitting diodes, and field emission display. This book may be the first to clearly point out the relationship between the size and the structure of the materials, which strongly affects their properties. Understanding these control parameters has important technological implications for energy conversion and storage, biotechnology, lighting and display, and so forth.