A Photocatalytic System for the Alleviation of Ocean Acidification and Antibiotic Pollution

Abstract

Ocean acidification and antibiotic pollution are two serious threats to marine ecosystems. One is caused by the uptake of increasing amounts of CO2 from the atmosphere and the other is a consequence of inshore mariculture. We have designed a novelty oxygen-doping carbon nitride (O-CN) photocatalyst for the degradation of a targeted antibiotic (ofloxacin, OFL) in acidified seawater. The catalyst could degrade OFL rapidly (k = 0.013 min-1) in the presence of CO32- and HCO3-. Notably, our photocatalytic system can take advantage of ocean acidification as more CO3•- radicals are produced from the extra carbonate/bicarbonate species derived from the dissolved CO2 in the seawater. This would facilitate the generation of new N-C-O (O1) groups on the O-CN surface. These O1 groups are the active sites for the formation of •OH radicals that can oxidize OFL and release CO2. This investigation offers a novel strategy for alleviating two environmental threats simultaneously.

Keywords: Seawater, Photocatalytic degradation, Carbon nitride, CO2