Improving the Performance of a Popular Nanocatalyst
Titanium dioxide (TiO2) is an inexpensive crystalline material that has long been used as white coloring in applications, ranging from paint to powdered doughnuts. When the titanium dioxide particle size is 0.00000005 inches, it can serve as a catalyst, a chemical phenomenon in which the titanium dioxide increases the efficiency and selectivity of chemical processes by providing alternative reaction pathways.
In recent years, the low cost and nontoxic properties of titanium dioxide nanocatalysts have led to their commercialization for solar water purification in third-world countries, for flexible solar cells fabricated by roll-to-roll printing, and for self-cleaning building materials. While chemists have long known that the reactivity of these nanocrystals depends critically on their shape and structure, there is little fundamental understanding of these dependencies. And there are no rational means for improving and optimizing their performance.
Melissa A. Hines, Chemistry and Chemical Biology, with her graduate students, is using atomic-scale microscopy to study the structure and reactivity of a variety of small molecules during their interaction with titanium dioxide surfaces. Using insights gained from these experiments, she and her team are developing new methods to improve the performance of these crystals, including the growth of surface-supported, nanoscale networks. The fundamental understanding gained from these experiments will help future applications, such as new types of batteries or solar cells with improved performance.