Font Size: a A A

Preparation, Electrochemical and Photocatalytic Studies on Inorganic and Organic Nanomaterials for Solar Energy Conversion

Posted on:2014-06-17Degree:Ph.DType:Dissertation
University:University of California, DavisCandidate:Chamousis, Rachel LeeFull Text:PDF
GTID:1451390008458980Subject:Chemistry
Abstract/Summary:
New, inexpensive and non-polluting energy technologies are of great importance for civilization. A promising source is solar energy, which can be photocatalytically converted into gaseous fuel or electricity. It has been hypothesized that nanomaterials may lead to improved photoelectrochemical (PEC), suspended photocatalytic, and photovoltaic cells. This particular field of study is vast considering the various ways nanomaterials can be synthesized, manipulated, and employed. Here, several different nanomaterials are studied as photocatalysts and as components in photoelectrochemical and photovoltaic cells. The purpose is to better understand charge transfer properties and energetics of these materials, and eventually, to help find a cheap, active, and sustainable photocatalyst for our ever-increasing energy demands.;Chapter 1 gives a brief introduction to the field of nanomaterials for solar energy conversion. The motivation for this research is given, water-splitting photocatalysis is explained, and the various ways nanomaterials can be employed are reviewed.;Chapter 2 explains how nanomaterials such as titanium dioxide and tungsten oxide can be used to photocatalytically decompose organic contaminants in wastewater while simultaneously producing electricity. Efficiency and power output analysis of derived photoelectrochemical cells revealed the highest published values for titanium dioxide electrodes under 395 nm illumination.;Chapter 3 discusses calcium niobate (TBACa2Nb3O 10, TBA = tetrabutylammonium) nanosheets as a photocatalyst for hydrogen evolution from aqueous methanol solution under UV illumination. Photoelectrochemical techniques were used to study the effects of ion modification of TBACa 2Nb3O10 on the energetics, specifically the position of the Fermi energy. The data shows a direct relationship between the position of the Fermi energy and the relative rate of hydrogen production.;Chapter 4 explains the fabrication and function of the first fractal electrode-based organic photovoltaic cells. Although the fractal electrode enhances the interfacial area between the light absorber and electrode, enhanced charge recombination results in reduced photocurrent for fractal silver.;Chapter 5 gives a selection of the photoelectrochemical properties of iridium dioxide nanoparticles and single-crystal tungsten oxide nanosheets. The data can be used to calculate the photo-onset values for each material.;Chapter 6 gives supporting information on calculating the power conversion efficiency of a PEC cell.
Keywords/Search Tags:Energy, Nanomaterials, Organic
Related items