Edson Roberto Leite - Böcker

The major problem facing new energy conversion and storage technologies remains device ef?ciency. Projects based on nanostructured materials can yield improved performance in devices involving electrochemical reactions and heterogeneous catalysis, such as fuel and solar cells, batteries, etc. Nanoscale structures drama- cally alter the surface reaction rates and electrical transport throughout the material, causing a dramatic improvement in energy storage, conversion, and generation. Furthermore, the design of nanoscale materials to be applied in alternative energy devices is a predictable way to develop a wide range of new technologies for a more sustainable future. Therefore, the goal of this book is to present basic fundamentals and the most relevant properties of nanostructured materials in order to improve alternative energy devices. This book begins with a chapter by Gratzel .. summarizing the use of mesoscopic thin ?lms and hybrid materials in the development of new kinds of regenerative photoelectrochemical devices. Applications include high-ef?ciency solar cells. In chapter two, Ribeiro and Leite describe assembly and properties of nanop- ticles.The chapter presents a review on the properties and main features of nanoscale materials, emphasizing the dependence of key properties on size for energy purposes. A general description is also given of nanoparticle synthesi- tion methods (mainly oxides), focusing on advances in tailoring controlled shape nanostructures.

The major problem facing new energy conversion and storage technologies remains device ef?ciency. Projects based on nanostructured materials can yield improved performance in devices involving electrochemical reactions and heterogeneous catalysis, such as fuel and solar cells, batteries, etc. Nanoscale structures drama- cally alter the surface reaction rates and electrical transport throughout the material, causing a dramatic improvement in energy storage, conversion, and generation. Furthermore, the design of nanoscale materials to be applied in alternative energy devices is a predictable way to develop a wide range of new technologies for a more sustainable future. Therefore, the goal of this book is to present basic fundamentals and the most relevant properties of nanostructured materials in order to improve alternative energy devices. This book begins with a chapter by Gratzel .. summarizing the use of mesoscopic thin ?lms and hybrid materials in the development of new kinds of regenerative photoelectrochemical devices. Applications include high-ef?ciency solar cells. In chapter two, Ribeiro and Leite describe assembly and properties of nanop- ticles.The chapter presents a review on the properties and main features of nanoscale materials, emphasizing the dependence of key properties on size for energy purposes. A general description is also given of nanoparticle synthesi- tion methods (mainly oxides), focusing on advances in tailoring controlled shape nanostructures.

Since the size, shape, and microstructure of nanocrystalline materials strongly impact physical and chemical properties, the development of new synthetic routes to  nanocrystals with controlled composition and morphology is a key objective of the nanomaterials community. This objective is dependent on control of the nucleation and growth mechanisms that occur during the synthetic process, which in turn requires a fundamental understanding of both classical nucleation and growth and non-classical growth processes in nanostructured materials.  Recently, a novel growth process called Oriented Attachment (OA) was identified which appears to be a fundamental mechanism during the development of nanoscale  materials. OA is a special case of aggregation that provides an important route by which nanocrystals grow, defects are formed, and unique—often symmetry-defying—crystal morphologies can be produced. This growth mechanism involves reversible self-assembly of primary nanocrystals followed by reorientation of the assembled nanoparticles to achieve structural accord at the particle-particle interface, the removal of adsorbates and solvent molecules, and, finally, the irreversible formation of chemical bonds to produce new single crystals, twins, and intergrowths. Crystallization and Growth of Colloidal Nanocrystals provides a current understanding of the mechanisms related to nucleation and growth for use in controlling nanocrystal morphology and physical-chemical properties, and is essential reading for any chemist or materials scientist with an interest in using nanocrystals as building blocks for larger structures. This book provides a compendium for the expert reader as well as an excellent introduction for advanced undergraduate and graduate students seeking a gateway into this dynamic area of research.