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Journal of Nanomaterials
Volume 2013, Article ID 596324, 7 pages
http://dx.doi.org/10.1155/2013/596324
Research Article

Preparation of Bismuth Oxide Photocatalyst and Its Application in White-light LEDs

1Ph.D. Program of Electrical and Communications Engineering, Feng Chia University, No. 100, Wen Hwa Road, Taichung 40724, Taiwan
2Department of Environmental Engineering and Science, Feng Chia University, No. 100, Wen Hwa Road, Taichung 40724, Taiwan
3Department of Materials Science and Engineering, Feng Chia University, No. 100, Wen Hwa Road, Taichung 40724, Taiwan
4Department of Photonics, Feng Chia University, No. 100, Wen Hwa Road, Taichung 40724, Taiwan
5Department of Applied Mathematics, Feng Chia University, No. 100, Wen Hwa Road, Taichung 40724, Taiwan
6Department of Electrical Engineering, Feng Chia University, No. 100, Wen Hwa Road, Taichung 40724, Taiwan

Received 10 July 2013; Accepted 14 September 2013

Academic Editor: Jiaguo Yu

Copyright © 2013 Yen-Chang Chu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Bismuth oxide photocatalysts were synthesized and coated on the front surface of phosphor-converted white light-emitting diodes to produce a safe and environmentally benign lighting source. Bismuth oxide photocatalyst powders were synthesized with a spray pyrolysis method at 500°C, 600°C, 700°C, and 800°C. Using the absorption spectrum in the blue and UV regions of the bismuth oxide photocatalysts, the blue light and UV leakage problems of phosphor-converted white LEDs can be significantly reduced. The experimental results showed that bismuth oxide photocatalyst synthesized at 700°C exhibited the most superior spectrum inhibiting ability. The suppressed ratio reached 52.33% in the blue and UV regions from 360 to 420 nm. Related colorimetric parameters and the photocatalyst decomposition ability of fabricated white-light LEDs were tested. The CIE chromaticity coordinates were (0.349, 0.393), and the correlated color temperature was 4991 K. In addition, the coating layer of photocatalyst can act as an air purifier and diffuser to reduce glare. A value of  ppmv of molecular formaldehyde gas can be decomposed in 120 mins.