Journal
ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS
Volume 7, Issue 2, Pages 70-75Publisher
AMER CHEMICAL SOC
DOI: 10.1021/acs.estlett.9b00704
Keywords
-
Categories
Funding
- National Natural Science Foundation of China (NSFC) project [D0510/91644218, D0512/41675145]
- National Key R&D Program of China [2016YFC0200500, 2016YFC0202000]
- NSFC [D0512/41875175, D0510/41605098]
- National Natural Science Foundation of China [91544213]
- Hong Kong Research Grants Council [A-PolyU502/16]
Ask authors/readers for more resources
Titanium dioxide (TiO2) is extensively used with the process of urbanization and potentially influences atmospheric chemistry, which is yet unclear. In this work, we demonstrated strong production of Cl-2 from illuminated KCl-coated TiO2 membranes and suggested an important daytime source of chlorine radicals. We found that water and oxygen were required for the reactions to proceed, and Cl-2 production increased linearly with the amount of coated KCl, humidity of the carrier gas, and light intensity. These results suggested that water promotes the reactivity of coated KCl via interaction with the crystal lattice to release free chloride ions (Cl-). The free Cl- transfer charges to O-2 via photoactivated TiO2 to form Cl-2 and probably the O-2(-) radical. In addition to Cl-2, ClO and HOCl were also observed via the complex reactions between Cl/Cl-2 and HOx. An intensive campaign was conducted in Shanghai, during which evident daytime peaks of Cl-2 were observed. Estimated Cl-2 production from TiO2 photocatalysis can be up to 0.2 ppb/h when the TiO2-containing surface reaches 20% of the urban surface, and highly correlated to the observed Cl-2. Our results suggest a non-negligible role of TiO2 in atmospheric photochemistry via altering the radical budget.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available