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Ren J, Lin L, Lieutenant K, Schulz C, Wong D, Gimm T, Bande A, Wang X, Petit T. Role of Dopants on the Local Electronic Structure of Polymeric Carbon Nitride Photocatalysts. SMALL METHODS 2021; 5:e2000707. [PMID: 34927893 DOI: 10.1002/smtd.202000707] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 10/02/2020] [Indexed: 06/14/2023]
Abstract
Polymeric carbon nitride (PCN) is a promising class of materials for solar-to-chemical energy conversion. The increase of the photocatalytic activity of PCN is often achieved by the incorporation of heteroatoms, whose impact on the electronic structure of PCN remains poorly explored. This work reveals that the local electronic structure of PCN is strongly altered by doping with sulfur and iron using X-ray absorption spectroscopy (XAS) and resonant inelastic X-ray scattering (RIXS). From XAS at the carbon and nitrogen K-edges, sulfur atoms are found to mostly affect carbon atoms, in contrast to iron doping mostly altering nitrogen sites. In RIXS at the nitrogen K-edge, a vibrational progression, affected by iron doping, is evidenced, which is attributed to a vibronic coupling between excited electrons in nitrogen atoms and C-N stretching modes in PCN heterocycling rings. This work opens new perspectives for the characterization of vibronic coupling in polymeric photocatalysts.
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Affiliation(s)
- Jian Ren
- Institute for Nanospectroscopy, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Straße 15, Berlin, 12489, Germany
- Department of Physics, Freie Universität Berlin, Arnimallee 14, Berlin, 14195, Germany
| | - Lihua Lin
- State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, 350002, China
| | - Klaus Lieutenant
- Department of Methods for Characterization of Transport Phenomena in Energy Materials, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Straße 15, Berlin, 12489, Germany
| | - Christian Schulz
- Department of Methods for Characterization of Transport Phenomena in Energy Materials, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Straße 15, Berlin, 12489, Germany
| | - Deniz Wong
- Department of Methods for Characterization of Transport Phenomena in Energy Materials, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Straße 15, Berlin, 12489, Germany
| | - Thorren Gimm
- Joint Research Group Simulation of Energy Materials, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, Berlin, 14109, Germany
| | - Annika Bande
- Young Investigator Group Theory of Electron Dynamics and Spectroscopy, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, Berlin, 14109, Germany
| | - Xinchen Wang
- State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, 350002, China
| | - Tristan Petit
- Institute for Nanospectroscopy, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Straße 15, Berlin, 12489, Germany
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Temperton RH, Skowron ST, Handrup K, Gibson AJ, Nicolaou A, Jaouen N, Besley E, O'Shea JN. Resonant inelastic X-ray scattering of a Ru photosensitizer: Insights from individual ligands to the electronic structure of the complete molecule. J Chem Phys 2019; 151:074701. [PMID: 31438696 DOI: 10.1063/1.5114692] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
N 1s Resonant Inelastic X-ray Scattering (RIXS) was used to probe the molecular electronic structure of the ruthenium photosensitizer complex cis-bis(isothiocyanato) bis(2,2'-bipyridyl-4,4'-dicarboxylato) ruthenium(II), known as "N3." In order to interpret these data, crystalline powder samples of the bipyridine-dicarboxylic acid ligand ("bi-isonicotinic acid") and the single ring analog "isonicotinic acid" were studied separately using the same method. Clear evidence for intermolecular hydrogen bonding is observed for each of these crystalline powders, along with clear vibronic coupling features. For bi-isonicotinic acid, these results are compared to those of a physisorbed multilayer, where no hydrogen bonding is observed. The RIXS of the "N3" dye, again prepared as a bulk powder sample, is interpreted in terms of the orbital contributions of the bi-isonicotinic acid and thiocyanate ligands by considering the two different nitrogen species. This allows direct comparison with the isolated ligand molecules where we highlight the impact of the central Ru atom on the electronic structure of the ligand. Further interpretation is provided through complementary resonant photoemission spectroscopy and density functional theory calculations. This combination of techniques allows us to confirm the localization and relative coupling of the frontier orbitals and associated vibrational losses.
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Affiliation(s)
- Robert H Temperton
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Stephen T Skowron
- School of Chemistry, University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Karsten Handrup
- Synchrotron Radiation Research, Department of Physics, Box 118, SE-221 00 Lund, Sweden
| | - Andrew J Gibson
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | | | - Nicolas Jaouen
- Synchrotron SOLEIL, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette, France
| | - Elena Besley
- School of Chemistry, University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - James N O'Shea
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, United Kingdom
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Sreekantan Nair Lalithambika S, Golnak R, Winter B, Atak K. Electronic Structure of Aqueous [Co(bpy) 3] 2+/3+ Electron Mediators. Inorg Chem 2019; 58:4731-4740. [PMID: 30932491 DOI: 10.1021/acs.inorgchem.9b00167] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
We report on the electronic structure of cobalt(II) tris-2,2'-bipyridine and cobalt(III) tris-2,2'-bipyridine in aqueous solution using resonant inelastic X-ray scattering (RIXS) spectroscopy at the Co L-edge and N K-edge resonances. Partial fluorescence yield X-ray absorption spectra at both edges were obtained by signal integration of the respective RIXS spectra. Experiments are complemented by calculations of the X-ray absorption spectra for high- and low-spin configurations using density functional theory/restricted open-shell configuration interaction singles and time-dependent density functional theory methods. We find that linear combinations of the simulated X-ray absorption spectra for different spin states reproduce the experimental spectra. Best agreement is obtained for measurements at the Co L-edge, for both samples. For cobalt(II) tris-2,2'-bipyridine, our combined experimental and computational study reveals ∼40% low-spin and ∼60% high-spin state components. Much stronger low-spin character is found for cobalt(III) tris-2,2'-bipyridine, ∼80% low spin and ∼20% high spin. Prominent energy-loss features in the Co RIXS spectra are indicative of d-d excitations and charge-transfer excitations due to strong mixing between metal and ligand orbitals in both complexes. Analysis of N 1s RIXS data reveals the emission from metal dominated orbitals in the valence region, supporting the strong metal-ligand mixing.
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Affiliation(s)
- Sreeju Sreekantan Nair Lalithambika
- Institute of Methods for Material Development , Helmholtz-Zentrum Berlin für Materialien und Energie , Albert-Einstein-Strasse 15 , 12489 Berlin , Germany.,Freie Universität Berlin , Fachbereich Physik , Arnimallee 14 , D-14195 Berlin , Germany
| | - Ronny Golnak
- Department of Highly Sensitive X-ray Spectroscopy , Helmholtz-Zentrum Berlin für Materialien und Energie , Albert-Einstein-Strasse 15 , 12489 Berlin , Germany
| | - Bernd Winter
- Department of Molecular Physics , Fritz-Haber-Institut der Max-Planck-Gesellschaft , Faradayweg 4-6 , D-14195 Berlin , Germany
| | - Kaan Atak
- Institute of Methods for Material Development , Helmholtz-Zentrum Berlin für Materialien und Energie , Albert-Einstein-Strasse 15 , 12489 Berlin , Germany
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O’Shea JN, Handrup K, Temperton RH, Gibson AJ, Nicolaou A, Jaouen N, Taylor JB, Mayor LC, Swarbrick JC, Schnadt J. Ultra-fast intramolecular vibronic coupling revealed by RIXS and RPES maps of an aromatic adsorbate on TiO2(110). J Chem Phys 2018; 148:204705. [DOI: 10.1063/1.5024862] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- James N. O’Shea
- School of Physics, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Karsten Handrup
- Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark
| | - Robert H. Temperton
- School of Physics, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Andrew J. Gibson
- School of Physics, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | | | - Nicolas Jaouen
- Synchrotron SOLEIL, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette, France
| | - John B. Taylor
- School of Physics, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Louise C. Mayor
- School of Physics, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Janine C. Swarbrick
- School of Physics, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Joachim Schnadt
- Division of Synchrotron Radiation Research, Department of Physics, Lund University, P.O. Box 118, 221 00 Lund, Sweden
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