Boon-im, Pattarapa
(2013)
SILVER PHOSPHATE NANOPARTICLE-EMBEDDED ZINC OXIDE NANOWIRE ARRAYS FOR PHOTOELECTROCHEMICAL SOLAR WATER SPLITTING.
Master's Thesis, University of Pittsburgh.
(Unpublished)
Abstract
Conversion of solar energy to storable chemical energy has received considerable interest in the past decade due to the limited availability of fossil fuels and concerns on environmental sustainability. One of the important processes involved in producing alternative fuels by utilizing solar energy is solar water splitting. One of the challenges in solar water splitting is to identify a semiconductor material that is capable to absorb major portion of the solar spectrum and possesses proper band edge potentials to simultaneously oxidize and reduce water. An alternative approach to the direct solar water splitting is photoelectrochemical solar water splitting, which physically separates the photoanode from photocathode for water oxidation and reduction, respectively, allowing each electrode to be independently optimized.
In this work, a composite photoanode consisting of Ag3PO4 nanoparticles embedded into ZnO nanowire arrays is fabricated for photoelectrochemical solar water splitting. The composite photoanode takes advantage of both the high photocatalytic activity of Ag3PO4 nanoparticles and the fast electron transport enabled by single crystalline ZnO nanowires. Ag3PO4 nanoparticles are able to harness visible light and possess higher photoactivity than most known semiconductors including BiVO4 and WO3 under visible light irradiation, thanks to the band structure of Ag3PO4 and the high internal surface area of Ag3PO4 nanoparticles. However, the efficiency of the photoanode made of Ag3PO4 nanoparticle films is limited by the slow electron transport between the disorderly packed Ag3PO4 nanoparticles and only very thin films of Ag3PO4 nanoparticles may be used. We have found that embedding the Ag3PO4 nanoparticles into ordered ZnO nanowire arrays may allow much thicker films of Ag3PO4 nanoparticles to be used and the photocurrent may be improved by up to six times compared to planar Ag3PO4/ZnO films, primarily due to the improved charge transportation enabled by the vertically ordered single crystalline ZnO nanowire arrays. Our result indicates that Ag3PO4 nanoparticles-embedded ZnO nanowire array is a promising composite photoanode for solar water splitting.
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Details
| Item Type: |
University of Pittsburgh ETD
|
| Status: |
Unpublished |
| Creators/Authors: |
|
| ETD Committee: |
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| Date: |
31 January 2013 |
| Date Type: |
Publication |
| Defense Date: |
19 November 2012 |
| Approval Date: |
31 January 2013 |
| Submission Date: |
26 November 2012 |
| Access Restriction: |
No restriction; Release the ETD for access worldwide immediately. |
| Number of Pages: |
52 |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
Swanson School of Engineering > Chemical Engineering |
| Degree: |
MS - Master of Science |
| Thesis Type: |
Master's Thesis |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
N/A |
| Date Deposited: |
31 Jan 2013 19:03 |
| Last Modified: |
15 Nov 2016 14:07 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/16574 |
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