In an article published in the journal Angewandte Chemie, chemists at Boston College detailed their breakthroughs in developing a way to harness artificial photosynthesis by narrowing the voltage gap between oxidation and reduction.
The team achieved the gains by coating hematite, an iron oxide similar to rust, and nickel iron oxide. They were able to narrow the voltage gap between reduction and oxidation to harness photosynthesis. This is important since researchers have been trying to harvest solar energy for years and store it efficiently in chemical bonds, such as in solar panels. Nature may produce clues about how to do this effectively. Not that mimicking nature is an easy feat.
Photosynthesis is made up of oxidation, which produces oxygen gas, and reduction, which produces organic molecules. In artificial photosynthesis, also called water splitting, scientists try to mimic oxidation and reduction by using a photoanode to oxidize water and a photocathode to either reduce water for hydrogen production or to reduce carbon dioxide for organic molecules.
The Boston College research team’s advances in photoanode development allowed the engineered nanowire structures to achieve a photovoltage of .6 volts using an iron oxide material. The voltage rose to 50 % results reported in 2012. The system of oxygen, silicon and iron — three of the four most abundant elements on earth – is able to provide more than 1 volt of power. Just two-tenths of a volt short on the photoanode – a substantial narrowing of the gap.