Functionalized nanostructures play a central role of ever-increasing importance in renewable energy applications and researches. There are many forms of nanostructures, most notably of which are nanoparticles (NP) and nanowires (NW). The former have great promise for optoelectronic and photovoltaic applications, while the latter can be used in sensor and energy-harvesting devices. For NPs, one major application is next-generation solar cells. Progress has been rapid in increasing the efficiency of energy conversion. However, extraction of the photo-generated charge carriers remains challenging. One key task is to greatly improve the charge carrier mobilities in NP solids, so that photo-generated electron/hole pair can be collected before recombining. The first crucial step to achieve this goal is to understand the fundamental underlying physics governing the transport. To study the transport properties in NP, we have developed the Hierarchical Nanoparticle Transport Simulator, or HiNTS. Details of theories and implementations of HiNTS are presented in this dissertation. We used HiNTS in various transport studies in NP solids, and reported three of them in this dissertation. First, we used HiNTS to simulate the metal-insulator transition (MIT) in NP films. Electrons transfer between neighboring NPs via activated hopping when the NP energies differ by more than an overlap energy, but transfer by a non-activated quantum delocalization, if the NP energies are closer than the overlap energy. As the overlap energy increases, emerging percolating clusters support a metallic transport across the entire film. We simulated the evolution of the temperature-dependent electron mobility. We analyzed our data in terms of two candidate models of the MIT: (a) as a Quantum Critical Transition, signaled by an effective gap going to zero; and (b) as a Quantum Percolation Transition, where a sample-spanning metallic percolation path is formed as the fraction of the hopping bonds in the transport paths is going to zero. We found that the Quantum Percolation Transition theory provides a better description of the MIT. We also observed an anomalously low gap region next to the MIT. We discussed the relevance of our results in the light of recent experimental measurements. Second, we analyzed charge transport in glassy binary NP films composed of large and small PbSe NPs. In films with small fractions of large NPs (LNPs), the LNPs act as traps for mobile charge carriers and the carrier mobility decreases with increasing LNP fraction f[subscript LNP]. For f[subscript LNP] above the percolation threshold f[subscript P], the LNPs form sample-spanning percolation networks that facilitate carrier transport. The increasing density of these percolation networks leads to a gradual recovery of the mobility as f[subscript LNP] approaches 1. Measurements of field-effect transistors made from mixtures of 6.5 nm and 5.1 nm PbSe NPs show a deep mobility minimum at f[subscript LNP] ~ 0.2. We used HiNTS to help explain the experimental results and elucidate the percolation physics of binary NP films. We explored the impact of ligand length, electron density, site energy disorder, charging energy, and temperature on the position (f[subscript LNP]) and depth of the mobility minimum. The simulation results can be understood in terms of a renormalized trap model, but the simulations fail to account for the weak temperature dependence of the mobility minimum observed in experiment unless mid-gap traps are assumed to play a key role in charge transport. Heat maps of electron residence times constructed from the simulations help to visualize transport within the percolation networks. The close comparison of experiment and simulations presented in this study is a promising systematic approach to unmasking the factors that control charge transport in NP films. Third, we used HiNTS to study the commensuration effects in Nanoparticle FETs (NP-FETs). For the case when the two NP layers closest to the gate are active for transport, our results include the following. (1) We observed the emergence of commensuration effects when the electron filling factors in both NP layers reached integer values. These commensuration effects were profound as they reduced the mobility all the way to zero. (2) We identified and characterized different classes of commensuration effects for different parameter regions. (3) We studied these commensuration effects in a four-dimensional parameter space, as a function of the on-site charging energy E[subscript C], the gate voltage V[subscript G], the disorder D, and the temperature k[subscript B]T. We explored the regions, or dynamical phases, in the parameter space characterized by the distinct commensuration effects. All three NP-related projects greatly advance our understanding of transport mechanism in NP solids, which is crucial in unlocking the full potential of NP in optoelectronic and photovoltaic applications. The rest of the dissertation switches focus to another two emerging nanostructures for renewable energy applications: First, we explored the potential use of nanowires for energy harvesting purposes. We have demonstrated the feasibility of using ZnO nanowires to harvest both mechanical and low-quality thermal energy in simple, scalable devices. These devices were fabricated on kapton films and used ZnO nanowires with the same growth direction to assure alignment of the piezoelectric potentials of all of the wires. Mechanical harvesting from these devices was demonstrated using a periodic application of force, modeling the motion of the human body. Tapping the device from the top of the device with a wood stick, for example yielded an Open Circuit Voltage (OCV) of 0.2-4 V, which is in an ideal range for device applications. To demonstrate thermal harvesting from low quality heat sources, a commercially available Nitinol (Ni-Ti alloy) foil was attached to the nanowire piezoelectric device to create a compound thermoelectric. When bent at room temperature and then heated to 50 ̊C, the Nitinol foil was restored to its original flat shape, which yielded an output voltage of nearly 1V from the ZnO nanowire device. In both cases, optimization of the nanowire device from materials selection and design geometry bode well for significant improvement over these initial results. Last but not least, we proposed a novel nanostructured photovoltaic desalination system, which comprises: a solar cell, configured to receive solar radiation, including an n-doped semiconductor layer, a p-doped semiconductor layer, the two semiconductor layers forming a p-n junction, and a nano-channel array, formed in the p-n junction; an input reservoir, coupled to the solar cell, the input reservoir configured to contain a salty fluid, and to release the salty fluid to the solar cell; an output fluid management system, coupled to the solar cell, the output fluid management system configured to receive an output fluid from the solar cell; wherein the channel array is configured to receive the salty fluid from the input reservoir, and to output the output fluid to the output fluid management system. This new design greatly reduces power consumption required for desalination.

Nanostructured, Functional, and Flexible Materials for Energy Conversion and Storage Systems gathers and reviews developments within the field of nanostructured functional materials towards energy conversion and storage. Contributions from leading research groups involved in interdisciplinary research in the fields of chemistry, physics and materials science and engineering are presented. Chapters dealing with the development of nanostructured materials for energy conversion processes, including oxygen reduction, methanol oxidation, oxygen evolution, hydrogen evolution, formic acid oxidation and solar cells are discussed. The work concludes with a look at the application of nanostructured functional materials in energy storage system, such as supercapacitors and batteries. With its distinguished international team of expert contributors, this book will be an indispensable tool for anyone involved in the field of energy conversion and storage, including materials engineers, scientists and academics. Covers the importance of energy conversion and storage systems and the application of nanostructured functional materials toward energy-relevant catalytic processes Discusses the basic principles involved in energy conversion and storage systems Presents the role of nanostructured functional materials in the current scenario of energy-related research and development

Advanced Nanomaterials and Their Applications in Renewable Energy presents timely topics related to nanomaterials' feasible synthesis and characterization, and their application in the energy fields. In addition, the book provides insights and scientific discoveries in toxicity study, with information that is easily understood by a wide audience. Advanced energy materials are important in designing materials that have greater physical, electronic, and optical properties. This book emphasizes the fundamental physics and chemistry underlying the techniques used to develop solar and fuel cells with high charge densities and energy conversion efficiencies. New analytical techniques (synchronous X-ray) which probe the interactions of particles and radiation with matter are also explored, making this book an invaluable reference for practitioners and those interested in the science. Provides a comprehensive review of solar energy, fuel cells, and gas storage from 2010 to the present Reviews feasible synthesis and modern analytical techniques used in alternative energy Explores examples of research in alternative energy, including current assessments of nanomaterials and safety Contains a glossary of terms, units, and historical benchmarks Presents a useful guide that will bring readers up to speed on historical developments in alternative fuel cells

This first ever reference book that focuses on metal chalcogenide semiconductor nanostructures for renewable energy applications encapsulates the state-of-the-art in multidisciplinary research on the metal chalcogenide semiconductor nanostructures (nanocrystals, nanoparticles, nanorods, nanowires, nanobelts, nanoflowers, nanoribbons and more). The properties and synthesis of a class of nanomaterials is essential to renewable energy manufacturing and this book focuses on the synthesis of metal chalcogendie nanostructures, their growth mechanism, optical, electrical, and other important properties and their applications in different diverging fields like photovoltaics, hydrogen production, theromelectrics, lithium battery, energy storage, photocatalysis, sensors. An important reference source for students, scientists, engineers, researchers and industrialists working on nanomaterials-based energy aspects associated with chemistry, physics, materials science, electrical engineering, energy science and technology, and environmental science.

Nanostructured, Functional, and Flexible Materials for Energy Conversion and Storage Systems gathers and reviews developments within the field of nanostructured functional materials towards energy conversion and storage. Contributions from leading research groups involved in interdisciplinary research in the fields of chemistry, physics and materials science and engineering are presented. Chapters dealing with the development of nanostructured materials for energy conversion processes, including oxygen reduction, methanol oxidation, oxygen evolution, hydrogen evolution, formic acid oxidation and solar cells are discussed. The work concludes with a look at the application of nanostructured functional materials in energy storage system, such as supercapacitors and batteries. With its distinguished international team of expert contributors, this book will be an indispensable tool for anyone involved in the field of energy conversion and storage, including materials engineers, scientists and academics. Covers the importance of energy conversion and storage systems and the application of nanostructured functional materials toward energy-relevant catalytic processes Discusses the basic principles involved in energy conversion and storage systems Presents the role of nanostructured functional materials in the current scenario of energy-related research and development

This book provides a comprehensive overview of engineering nanostructures mediated by functional polymers in combination with optimal synthesis and processing techniques. The focus is on polymer-engineered nanostructures for advanced energy applications. It discusses a variety of polymers that function as precursors, templates, nano-reactors, surfactants, stabilizers, modifiers, dopants, and spacers for directing self-assembly, assisting organization, and templating growth of numerous diverse nanostructures. It also presents a wide range of polymer processing techniques that enable the efficient design and optimal fabrication of nanostructured polymers, inorganics, and organic–inorganic nanocomposites using in-situ hybridization and/or ex-situ recombination methodologies. Combining state-of-the-art knowledge from polymer-guided fabrication of advanced nanostructures and their unique properties, it especially highlights the new, cutting-edge breakthroughs, future horizons, and insights into such nanostructured materials in applications such as photovoltaics, fuel cells, thermoelectrics, piezoelectrics, ferroelectrics, batteries, supercapacitors, photocatalysis, and hydrogen generation and storage. It offers an instructive and approachable guide to polymer-engineered nanostructures for further development of advanced energy materials to meet ever-increasing global energy demands. Interdisciplinary and broad perspectives from internationally respected contributors ensure this book serves as a valuable reference source for scientists, students, and engineers working in polymer science, renewable energy materials, materials engineering, chemistry, physics, surface/interface science, and nanotechnology. It is also suitable as a textbook for universities, institutes, and industrial institutions.

This book addresses the fabrication of responsive functional nanomaterials and their use in sustainable energy and environmental applications. Responsive functional nanomaterials can change their physiochemical properties to adapt to their environment. Accordingly, these novel materials are playing an increasingly important role in a diverse range of applications, such as sensors and actuators, self-healing materials, separation, drug delivery, diagnostics, tissue engineering, functional coatings and textiles. This book reports on the latest advances in responsive functional nanomaterials in a wide range of applications and will appeal to a broad readership across the fields of materials, chemistry, sustainable energy, environmental science and nanotechnology.