Artificial Photosynthesis: Optimization of proton reduction catalysis

My name is Ryan DiRisio, and I am a junior at the College majoring in chemistry.

If the Earth continues to rely on fossil fuels as our primary energy source, there will be severe consequences in the environment: global average temperature will increase, extreme weather will occur more frequently, and the ocean will acidify, destroying ecosystems.  In order to combat this, alternative energies are being developed.  Solar energy has shown promise, since it is almost universal in its availability.  However, traditional photovoltaics are expensive and inefficient, especially when attempting to store the harvested energy in batteries.  One novel approach to solar energy Artificial Photosynthesis (AP).  The point of AP is to mimic Nature; in traditional photosynthesis, a plant is irradiated, prompting a splitting of water into protons and oxygen gas.  The electron released from this reaction is then used to reduce NADP+ to NADP.  This, effectively, stores energy in the form of a chemical bond.  In a traditional AP scheme, water is split into protons and hydrogen gas, as in traditional photosynthesis.  Then, however, the proton is reduced to hydrogen gas.  This hydrogen produced can then be ignited as a carbon-neutral energy source, producing water vapor as a by-product.  In our lab, we focus on the reductive side of AP.  In our proton reduction setup, we irradiate a photosensitizer, sacrificial electron donor, catalyst, ethanol, and water with light and measure the amount of hydrogen produced over time to gauge activity and robustness.  Over the summer, I will be continuing this research through the optimization of our experimental setup.  I will accomplish this through varying photosensitizers and catalysts, as well as adjusting the concentrations of the components to maximize activity.