CdSe Quantum Dots In Resorcinol Gel Matrix For Applications In Water Purification

Friday, 13 February 2015
Exhibit Hall (San Jose Convention Center)
Adithya Iyengar, Durham, NC
Water pollution involving organic materials is a threatening problem in society today. The objective of our research was to investigate the effect photosensitized quantum dots have on the degradation of organic pollutants. Photosensitized quantum dots are shown to degrade organic materials in the same way functionalized PM25 TiO2 does. However, the tunability of quantum dots allows them to work in both the visible and UV spectrum, a feature that TiO2 does not have. In our experiment, we used cadmium Selenium quantum dots that were bounded to a carbon gel for this purpose. After creating the CdSe quantum dots, we synthesized a resorcinol-formaldehyde gel that was used to contain the quantum dots inside of a gel matrix. First, a methyl orange test was conducted to examine degradation of a methyl orange solution (organic pollutant simulant) over time. Quantum dots are also toxic substances, made of octadecene and cadmium, both of which pose health hazards. In order to prevent water contamination, we had to ensure that the quantum dots were completely embedded in the resorcinol-formaldehyde carbon gel. Next, using an ultraviolet spectrometer, the quantum dots were tested to verify that they did not leach out of the gel and into the water source. The UV Spectroscopy test indicated that the quantum dots did not leach out of the gel complex, as the fluorescence was the same in the gel with quantum dots as the gel without the quantum dots. Additionally, the quantum dots were able to degrade the methyl orange. At the wavelength of 500.7 nm, the absorbance of the solution decreased over time, which represented the degradation of the organic pollutant simulant. The gel complex containing the quantum dots was able to restrain the dots inside, representing a safe method to use toxic quantum dots to degrade organic pollutants in water.