Abiotic Oxygen Synthesis

2.4 billion years ago, before any photosynthetic organisms existed on Earth, the atmosphere was composed mostly of carbon dioxide. Scientists have postulated over the past 40 years that there must have been a small amount of oxygen in the atmosphere as well, although there wasn’t clear evidence explaining where this oxygen came from or how it was sustained. It was originally thought that oxygen was synthesized from carbon dioxide through a two-step process, but now new research from a U.C Davis graduate student, Zhou Lu, shows how diatomic oxygen can be synthesized from carbon dioxide in one step. In his research, Lu irradiated O₂ with a vacuum ultraviolet laser, which disassociated the CO₂ into O₂ and a single C. The laser is a “vacuum” laser because the particular wavelength of light is absorbed by air, so in order to attain this result, the experiment was conducted in special ion imaging apparatus developed at U.C. Davis. This process is likely going on even now in the upper atmosphere, where this type of light is bombarding Earth from the sun. This process helps explain how oxygen was synthesized and maintained in the early atmosphere of Earth.  

http://blogs.ucdavis.edu/egghead/2014/10/02/making-oxygen-before-life/

Submitted by Andrew Delahunty