Methods for Increasing the Efficiency of Power Generation from Water Evaporation

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Kumar, Rahul
The conversion of ambient thermal energy into electrical energy is a fascinating and simple phenomenon that has the potential to meet the world’s growing electrical demands. When water molecules flow through the nanopores of functionalized nanomaterials, their evaporation can be driven by thermal energy, leading to the aforementioned electrical conversion, called as hydrovoltaic effect. However, due to low power output, poor flexibility, complex synthesis, low stability, weather sensitive operating conditions, and lower strength, power generation using this technique is not commercially viable. Selecting a nanomaterial that is porous, electricallyconductive, strong, and both chemically and thermally stable in water could be an approach to develop a more commercially viable device. However, we must optimize all of these parameters if we want a device with good performance. Another important consideration in device design and optimization is electrode connections, improving performance and avoiding a short-circuit requires optimal electrode choice and placement. This thesis aims to address the issues in the field through detailed observations and experimental data. This thesis contains following chapters: Chapter 1 which discusses the origin of hydrovoltaics, the mechanism of power generation, different types of hydrovoltaics, limitations with different type of hydrovoltaics, key elements to make a better hydrovoltaic cell, applications of hydrovoltaics, measuring techniques for hydrovoltaics performance, and Conclusions Chapter 2: Fabrication of aluminium oxide on TLC which is functional in different weather conditions, Chapter 3: High-performance devices developed using functionalized multi-walled carbon nanotubes with power outputs 10 times higher than most devices in the field., Chapter 4: Tuning the functionalization of graphite which generated a current density three orders of magnitude higher than the previously reported graphene-based devices. These helped elucidate how different parameters affect the power output and what are the best electrode combinations and their placements for different types of materials. Chapter 2-4 are reported in manuscript form and necessary details are given in appendices.
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