Lawrence Livermore National Laboratory



Allan Chang

Overview

Our research demonstrated the feasibility of enhancing the photocatalytic removal of organic contaminants in water by incorporating plasmonic nanostructures with the photocatalyst to substantially increase the catalysis reaction rate. Specifically, we demonstrated up to five-times enhancement in the reaction rate of photocatalytic decomposition of an organic chemical (methyl orange) dissolved in water, by incorporating a layer of aluminum plasmonic nanostructures on top of a titanium dioxide thin film photocatalyst.

The plasmonics-induced electromagnetic field enhancement significantly increased photo-absorption and electron-hole pair generation at the catalyst surface, thereby enhancing the redox reactions at the catalyst–water interface to break dissolved organics into non-toxic byproducts such as carbon dioxide. Our results also point to the potential for a rate enhancement factor of over twenty times with further design optimization and improved fabrication.

Impact on Mission

The success of a plasmonic photocatalyst allows us to greatly enhance our current capabilities in water security and technology. The ability to provide efficient and rapid water purification and recycling helps meet DOE and broader national needs for energy and resource security. Our techniques in this project extend to Lawrence Livermore National Laboratory's mission focus area of chemical and biological countermeasures by adding potential tools to decontaminate and neutralize threats to our water infrastructure. Furthermore, we established new nanosphere lithography capability at the Laboratory that can be applied to a range of other important research activities requiring low cost, fast nanopatterning.

Publications, Presentations, Etc.

Brisbin, R. et al. 2019. "Paving the Way for Plasmonic-Enhanced Photocatalytic Water Purification: Comparison of Rate Constants of Photochemical Methyl Orange Decomposition." Lawrence Livermore National Laboratory Summer Student Poster Symposium, Livermore, CA, August 2019. LLNL-POST-785137.