Photostability and Thermal Decomposition of Benzoic Acid on TiO2

详细信息    查看全文

• 作者：Elizabeth C. Landis ; Stephen C. Jensen ; Katherine R. Phillips ; Cynthia M. Friend
• 刊名：The Journal of Physical Chemistry C
• 出版年：2012
• 出版时间：October 11, 2012
• 年：2012
• 卷：116
• 期：40
• 页码：21508-21513
• 全文大小：452K
• 年卷期：v.116,no.40(October 11, 2012)
• ISSN：1932-7455

文摘

Carboxylic acid moieties are used to anchor organic dyes to TiO₂ in many applications; therefore, their structure, distribution on the surface, and thermal and photochemical stability are extremely important. Herein, we investigate the thermal and photochemistry of benzoic acid monolayers on TiO₂. Benzoic acid deprotonates to form benzoate monomers on the TiO₂ surface, and thermally decomposes to benzene and CO. Titanium interstitials migrate to the surface and react with oxygen atoms from the benzoate molecules to form new TiO_x islands. A combination of X-ray photoelectron spectroscopy and scanning tunneling microscopy shows that the benzoate layer on TiO₂ is stable under UV illumination for several hours. The stability of benzoate under illumination is in contrast to the photochemical instability of other small carboxylic acid containing molecules on TiO₂ and demonstrates the importance of substituents on the stability of the molecular layer.