Nizkorodov-George study shows new way OH forms

AirUCI Co-Director Sergey Nizkorodov and AirUCI collaborator Christian George of the National Center for Scientific Research at the University of Lyon, France, have published a paper in the Proceedings of the National Academy of Sciences that offers a new understanding of how hydroxide (OH) molecules help clear the atmosphere of human-emitted pollutants and greenhouse gases.  They found that a strong electric field that exists at the interface between airborne water droplets and the surrounding air can create OH by a previously unknown mechanism.  “OH is a key player in the story of atmospheric chemistry.  It initiates the reactions that break down airborne pollutants and helps to remove noxious chemicals such as sulfur dioxide and nitric oxide, which are poisonous gases, from the atmosphere,” says Christian, lead author on the study. 

The current common assumption is that sunlight is the chief driver of OH formation in the atmosphere.  Their research found that OH production rates in darkness mirror those and even exceed rates from drivers like sunlight exposure.  “Enough OH will be created to compete with other known OH sources,” said Sergey.  “At night, when there is no photochemistry, OH is still produced and it is produced at a higher rate than would otherwise happen.” " In the pure water itself, OH can be created spontaneously by the special conditions on the surface of the droplets.”  Read the article