2025-11-06 立命館大学
立命館大学生命科学部の小林洋一教授らの研究チームは、環境汚染物質「永遠の化学物質」PFASのうち、最も分解困難とされるPFOSおよびPFOAを低毒性ZnOナノ結晶と市販近紫外LED光で常温・常圧下に分解・無害化することに成功した。酢酸で表面修飾したZnOナノ結晶を触媒とし、光照射10時間でPFOS残存率を0.5%まで低減、触媒回転数（TON）は8,250を記録した。生成したフッ化物イオンはカルシウムと反応させることで蛍石として再資源化でき、環境修復と資源循環の両立を実証。ZnOは安価で大量合成可能な無害材料であり、従来の高温・強酸化法に代わる持続可能な光触媒分解技術として注目される。成果はChemical Science誌に掲載された。
図．近紫外光 LED を用いた、ZnO ナノ結晶による PFAS の還元的光分解のメカニズム
＜関連情報＞
- https://www.ritsumei.ac.jp/profile/pressrelease_detail/?id=1240
- https://www.ritsumei.ac.jp/file.jsp?id=673967&f=.pdf
- https://pubs.rsc.org/en/content/articlelanding/2025/sc/d5sc05781g
表面処理されたZnOナノ結晶によるパーフルオロアルキル化合物の光触媒脱フッ素化 Photocatalytic defluorination of perfluoroalkyl substances by surface-engineered ZnO nanocrystals
Shuhei Kanao,Mai Yamaguchi,Yuto Toyota,Yuki Nagai and Yoichi Kobayashi
Chemical Science Published:05 Nov 2025
DOI:https://doi.org/10.1039/D5SC05781G
Abstract
Perfluoroalkyl substances (PFASs) are widely used due to their exceptional chemical stability. However, this also causes severe environmental persistence, bioaccumulation, and recycling challenges, making PFAS contamination a global issue. Conventional defluorination methods require excessive energy, limiting practical application. Therefore, developing an energy-efficient approach under ambient conditions is crucial for mitigating environmental risks and enabling fluorine material recycling. Here, we demonstrate that zinc oxide (ZnO) nanocrystals (NCs) capped with specific ligands can efficiently defluorinate perfluorooctanesulfonic acid (PFOS), which is one of the most stable PFASs, by irradiation of near UV light under ambient conditions. While NCs capped with mercaptopropionic acid achieved only 8.4% defluorination after 24 hours of 365 nm LED light irradiation, NCs capped with acetic acid exhibit 64% defluorination, reaching 92% for 24 h irradiation under optimized conditions. We further reveal that each NC can break approximately 8250 C–F bonds with high repeatability. The low toxicity, cost-effectiveness, and scalability of ZnO NCs make it a promising material for practical applications of PFAS decomposition.
