Experimental study for adsorption and photocatalytic reaction of ethyl methylphosphonate molecule as organophosphorus compound adsorbed at surface of titanium dioxide under UV irradiation in ambient condition

• Published in: Research on chemical intermediates 2021-04, Vol.47 (4), p.1563-1579
• Main Authors: Hirakawa, Tsutomu, Nishimoto, Chifumi K., Komano, Asuka, Otsuka, Mai, Negishi, Nobuaki, Miyaguchi, Hajime, Seto, Yasuo, Takeuchi, Koji
• Format: Article
• Language: English
• Subjects: Acceleration; Adsorption; Catalysis; Chemistry; Chemistry and Materials Science; Fourier transforms; Infrared reflection; Infrared spectroscopy; Inorganic Chemistry; Organophosphorus compounds; Phosphonic acids; Phosphoric acid; Photocatalysis; Photodegradation; Physical Chemistry; Reaction mechanisms; Surface chemistry; Titanium; Titanium dioxide; Ultraviolet radiation; Vibration mode
• ISSN: 0922-6168; 1568-5675
• DOI: 10.1007/s11164-020-04389-0

The adsorption and photocatalytic degradation of Ethyl methylphosphonate (EMPA) on powdery TiO 2 film has experimentally investigated using attenuated total reflection-infrared Fourier transform spectroscopy (ATR-FTIR) in ambient condition. Characteristic IR frequency as P-O-C vibration mode as EtO was observed by EMPA adsorbed at the surface of TiO 2 . By TiO 2 photocatalysis, the adsorbed EMPA was decomposed to methyl phosphonic acid and phosphoric acid. The increment of IR intensity of which is assigned to Ti–O-P-O-Ti of EMPA was accompanied with increasing the IR peak intensity assigned to MPA. About that, we suggest that the appearance of the Ti–O-P-O-Ti of EMPA by the TiO 2 photocatalysis is regarded as acceleration of the hydrolysis of EMPA by the surface OH groups of TiO 2 . The plausible adsorption structure and the photocatalytic reaction mechanism of EMPA at the surface of TiO 2 photocatalyst were elucidated.