Electronic Energy Levels and Band Alignment for Aqueous Phenol and Phenolate from First Principles

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• 作者：Daniel Opalka ; Tuan Anh Pham ; Michiel Sprik ; Giulia Galli
• 刊名：Journal of Physical Chemistry B
• 出版年：2015
• 出版时间：July 30, 2015
• 年：2015
• 卷：119
• 期：30
• 页码：9651-9660
• 全文大小：575K
• ISSN：1520-5207

文摘

Electronic energy levels in phenol and phenolate solutions have been computed using density functional theory and many-body perturbation theory. The valence and conduction bands of the solvent and the ionization energies of the solutes have been aligned with respect to the vacuum level based on the concept of a computational standard hydrogen electrode. We have found significant quantitative differences between the generalized-gradient approximation, calculations with the HSE hybrid functional, and many-body perturbation theory in the G₀W₀ approximation. For phenol, two ionization energies below the photoionization threshold of bulk water have been assigned in the spectrum of Kohn鈥揝ham eigenvalues of the solution. Deprotonation to phenolate was found to lift a third occupied energy level above the valence band maximum of the solvent which is characterized by an electronic lone pair at the hydroxyl group. The second and third ionization energies of phenolate were found to be very similar and explain the intensity pattern observed in recent experiments using liquid-microjet photoemission spectroscopy.