Duan, LijieWang, BoHeck, Kimberly N.Clark, Chelsea A.Wei, JinshanWang, MinghaoMetz, JordinWu, GangTsai, Ah-LimGuo, SujinArredondo, JacobMohite, Aditya D.Senftle, Thomas P.Westerhoff, PaulAlvarez, PedroWen, XianghuaSong, YonghuiWong, Michael S.2022-08-082022-08-082022Duan, Lijie, Wang, Bo, Heck, Kimberly N., et al.. "Titanium oxide improves boron nitride photocatalytic degradation of perfluorooctanoic acid." <i>Chemical Engineering Journal,</i> 448, (2022) Elsevier: https://doi.org/10.1016/j.cej.2022.137735.https://hdl.handle.net/1911/113051Boron nitride (BN) has the newly-found property of degrading recalcitrant polyfluoroalkyl substances (PFAS) under ultraviolet C (UV-C, 254 nm) irradiation. It is ineffective at longer wavelengths, though. In this study, we report the simple calcination of BN and UV-A active titanium oxide (TiO2) creates a BN/TiO2 composite that is more photocatalytically active than BN or TiO2 under UV-A for perfluorooctanoic acid (PFOA). Under UV-A, BN/TiO2 degraded PFOA ∼ 15 × faster than TiO2, while BN was inactive. Band diagram analysis and photocurrent response measurements indicated that BN/TiO2 is a type-II heterojunction semiconductor, facilitating charge carrier separation. Additional experiments confirmed the importance of photogenerated holes for degrading PFOA. Outdoor experimentation under natural sunlight found BN/TiO2 to degrade PFOA in deionized water and salt-containing water with a half-life of 1.7 h and 4.5 h, respectively. These identified photocatalytic properties of BN/TiO2 highlight the potential for the light-driven destruction of other PFAS.engThis is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Elsevier.Journal articlehttps://doi.org/10.1016/j.cej.2022.137735