Grantee Research Project Results
Design and Fabrication of High Surface Area Photocatalytic Nanostructures for High Efficiency Solar Degradation of Environmental PollutantsEPA Grant Number: F5B20297
Title: Design and Fabrication of High Surface Area Photocatalytic Nanostructures for High Efficiency Solar Degradation of Environmental Pollutants
Investigators: Forman, Arnold J.
Institution: University of California - Santa Barbara
EPA Project Officer: Jones, Brandon
Project Period: January 1, 2006 through December 31, 2008
Project Amount: $111,344
RFA: STAR Graduate Fellowships (2005)
Research Category: Academic Fellowships
The objective of this research is to optimize the efficiency of converting sunlight into redox active electron/hole pairs at a solid photocatalyst for organic pollutant degradation in ultrahigh surface area metal oxide semiconducting nanostructures.
There are no cost-effective solutions for continuous degradation of persistent organic atmospheric and aqueous pollutants. Data showing ecological problems associated with unregulated organic pollutants found in urban air and drinking water such as those from personal care products (synthetic fragrances), nonprescription drugs (unmetabolized by body, terminate in environment), and birth control pills (estrogens), in addition to hundreds of regulated organics such as pesticides, herbicides and petroleum derivatives is becoming increasingly common. The long term, chronic exposure effects of these and many other organic compounds on human health and the global ecosystem are not yet completely understood. However, what is certain is that studies in the field continually identify new toxic pathways for both regulated and unregulated anthropogenicly derived organic compounds in our environment. It is the complete degradation to inert products of these organic pollutants, not simply their removal or containment, via cost effective photocatalysis that is the basis of this research.Approach:
Recently, we have discovered a non-toxic electrochemical synthesis route for fabrication of ultrahigh surface area nanostructured metal oxide semiconductor photocatalysts (UNMOPs) via a one step synthesis. This methodology will be employed for synthesis of single component and/or mixed host-metal oxide UNMOPs with metals such as Ti, W, Fe, Mn, Cu, Zn, Mg and Ni. These metal oxides, which have a history of photocatalytic activities, will be made into low cost, environmentally benign nanostructures and tested under various photocatalytic pollutant degradation scenarios.
The cost efficiency of any such catalyst is key when considering product development and application and can be insured by selecting and optimizing only these materials which are inexpensive, environmentally benign, and amenable to large scale production.Expected Results:
Specifically, I seek to obtain fundamental data on the relationships between the composition and structure of solid-state photocatalyst nanomaterials and their catalytic function in complete organic pollutant degradation. The electron transport mechanism and overall photon-to-product conversion efficiency for this degradation process can be experimentally quantified and simultaneously optimized in our labs using high throughput combinatorial synthesis and screening methods. By tailoring metal oxide composition and morphology an ideal photocatalytic structure can be elucidated.Supplemental Keywords:
Photocatalyst, Inorganic material, Nanomaterial, Nanostructure, Nanoparticle, Electron transport, Electrochemical synthesis, Metal oxide, Semiconductor, Bandgap, Electron-hole pair, Redox, Hot carrier, Quantum efficiency, Ballistic transport, Organic pollutant, Combinatorial synthesis, Scanning Electron Microscope (SEM), X-Ray Diffraction (XRD), X-Ray Photoelectron Spectroscopy (XPS), Energy Dispersive X-Ray Spectroscopy (EDX / EDS), Scanning Tunneling Microscopy (STM), High Resolution Transmission Electon Microscopy (HRTEM), Gas Chromatography / Mass Spectrometry (GC/MS), Ultra Violet / Visible Spectroscopy (UV/Vis), Diffuse reflectance Infrared (IR) Spectroscopy,, RFA, Scientific Discipline, Sustainable Industry/Business, Chemical Engineering, Sustainable Environment, Technology for Sustainable Environment, Environmental Engineering, UNMOPs, nanotechnology, solar degradation, nanoparticles, ultrahigh surface area nanostructured metal oxide semiconducting photocatalysts