Urban Surface Chemistry

Urban surfaces accumulate a complex film known as “urban grime” — a mixture of organic and inorganic compounds deposited from traffic emissions, cooking, and other anthropogenic activities. We study how sunlight drives heterogeneous photochemical reactions on these surfaces.

Our research has revealed that these light-induced reactions on urban grime can produce significant amounts of HONO (nitrous acid), a key precursor of OH radicals in the urban atmosphere. This work has important implications for understanding urban air quality.