Adsorption and photocatalytic splitting of water on graphitic carbon nitride
- Graphitic carbon nitride, g-C₃N₄, is a promising organic photo-catalyst for a variety of redox reactions. In order to improve its efficiency in a systematic manner, however, a fundamental understanding of the microscopic interaction between catalyst, reactants and products is crucial. Here we present a systematic study of water adsorption on g-C₃N₄ by means of density functional theory and the density functional based tight-binding method as a prerequisite for understanding photocatalytic water splitting. We then analyze this prototypical redox reaction on the basis of a thermodynamic model providing an estimate of the overpotential for both water oxidation and H⁺ reduction. While the latter is found to occur readily upon irradiation with visible light, we derive a prohibitive overpotential of 1.56 eV for the water oxidation half reaction, comparing well with the experimental finding that in contrast to H₂ production O₂ evolution is only possible in the presence of oxidation cocatalysts.
Author details: | Jonas WirthGND, Rainer Neumann, Markus AntoniettiORCiDGND, Peter SaalfrankORCiDGND |
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DOI: | https://doi.org/10.1039/c4cp02021a |
ISSN: | 1463-9076 |
ISSN: | 1463-9084 |
Title of parent work (English): | physical chemistry, chemical physics : PCCP |
Subtitle (English): | a combined first principles and semiempirical study |
Publication type: | Article |
Language: | English |
Date of first publication: | 2014/06/25 |
Publication year: | 2014 |
Publishing institution: | Universität Potsdam |
Release date: | 2015/04/28 |
Tag: | augmented-wave method; hydrogen; initio molecular-dynamics; oxidation; photooxidation; reduction; simulations; tight-binding; transition; visible-light |
Volume: | 2014 |
Issue: | 16 |
Number of pages: | 10 |
First page: | 15917 |
Last Page: | 15926 |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Chemie |
DDC classification: | 5 Naturwissenschaften und Mathematik / 54 Chemie / 540 Chemie und zugeordnete Wissenschaften |
Peer review: | Referiert |
Publishing method: | Open Access |
Grantor: | RSC |
License (English): | Creative Commons - Namensnennung 3.0 Unported |
External remark: | Zweitveröffentlichung als Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe ; 172 |