Cottrell College Science Awards - 2014
Synthesis and Electrochemistry of Pyridine- and Phosphine-Stabilized Iridium Oxide Nanoparticles in Solutions and Films
Plants produce fuel (photosynthesis) by absorbing various wavelengths of sunlight and using that energy to form chemical compounds, which the plants then combine with oxygen – a process known as oxidation (burning).
Forming chemical compounds and then burning them requires making and breaking chemical bonds. These bonds are dependent upon atoms, such as oxygen and hydrogen, exchanging their outermost particles, electrons, to form larger assemblies called molecules.
But the devil, as they say, is in the details.
Thus, researchers around the world have been struggling for decades to create an artificial photosynthesis process that is highly efficient and cost-effective, one that will yield clean, renewable fuels for our cars, trucks and planes.
Lloyd Horne, an assistant professor of chemistry at Murray State University,is investigating what appears to be a key pathway toward artificial photosynthesis – splitting the water molecule, H2O, into its hydrogen and oxygen components. (In some scenarios, the resulting hydrogen is subsequently used to make methanol, the simplest form of alcohol, a readily burnable liquid fuel.)
Specifically, Horne and his students are attempting to synthesize and study various forms of iridium oxide nanoparticles in solutions and thin films for use as a catalyst in splitting water. Translation:
-- Iridium oxide is currently one of the best catalysts used in splitting H2O. A catalyst furthers a chemical reaction – forming or breaking bonds -- without itself being consumed or altered in the process;
-- Nanoparticles are very tiny – a nanometer is vanishingly small, one-billionth of a meter. Matter and energy behave differently at the nanoscale, leading scientists to hope they can boost the efficiencies of chemical and electrical activities;
-- Thin films are just what the words imply – but probably more so. In some cases, they can be as thin as one or two layers of nanoparticles, or molecules.
Horne hopes to optimize the performance of iridium oxide nanoparticles by gaining insight into how their size, dispersal, structure, formation, and composition affect their ability to break the bonds of water molecules.