uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Tailoring the Electron-Rich Moiety in Benzothiadiazole-Based Polymers for an Efficient Photocatalytic Hydrogen Evolution Reaction
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.ORCID iD: 0000-0002-5853-0819
Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. Uppsala University.ORCID iD: 0000-0003-0377-3669
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.ORCID iD: 0000-0001-5192-0016
2019 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 123, no 42, p. 25531-25542Article in journal (Refereed) Published
Abstract [en]

Polymeric materials containing an extended π-conjugated backbone have shown a wide range of applicability including photocatalytic activity for the hydrogen evolution reaction (HER). The latter requires highly efficient materials with optimal light absorption and thermodynamic driving force for charge transfer processes, properties that are tailored by linking chemical units with distinct electron affinity to form a donor−acceptor architecture. Here, this concept is explored by means of ab initio theory in benzothiadiazole-based polymers with varying electron-rich moieties, viz., fluorene (PFO), cyclopentadithiophene (CPT), methoxybenzodithiophene (O-BzT), thiophenebenzodithiophene (T-BzT), and thiophene (T, VT)and thienethiophene (TT, VTT)-based units. All materials exhibit a red-shifted absorption spectrum with respect to the reference polymer (PFO-DT-BT) while keeping the catalytic power for hydrogen production almost unchanged. In particular, a displacement ofΔλ = 167 nm in the first absorption maximum has been achieved upon combination of chemical units with high donating character in CPT-VTT-BT. Furthermore, the exciton binding energies (Eb) have been systematically investigated to unveil the effects of geometry relaxation, environment polarity, and finite temperature contributions to the free energy. For instance, we show a significant change in Eb when going from the gas phase (Eb = 1.43−1.85 eV) to the solvent environment (Eb = 0.29−0.54 eV in 1-bromooctane with ε = 5.02). Furthermore, we have found a linear correlation between the lowering of exciton binding energies and the increasing of the ratio between donor and acceptor contributions to the HOMO orbital. This is a consequence of increased donating ability and enhanced spatial separation of electron−hole pairs, which weakens their interaction. Finally, our findings reveal that the donor unit plays a crucial role in key properties that govern the photocatalytic activity of donor−acceptor polymers contributing to the development of a practical guideline to design more efficient photocatalysts for the HER. This goes through a proper combination of electron-rich moieties to tune the optical gap, favor thermodynamic driving force for charge transfer, and lower exciton binding energies.

Place, publisher, year, edition, pages
2019. Vol. 123, no 42, p. 25531-25542
National Category
Atom and Molecular Physics and Optics
Research subject
Physics with specialization in Quantum Chemistry
Identifiers
URN: urn:nbn:se:uu:diva-395873OAI: oai:DiVA.org:uu-395873DiVA, id: diva2:1365468
Available from: 2019-10-24 Created: 2019-10-24 Last updated: 2019-10-28

Open Access in DiVA

No full text in DiVA

Authority records BETA

Damas, GianeMarchiori, CleberAraujo, Carlos Moyses

Search in DiVA

By author/editor
Damas, GianeMarchiori, CleberAraujo, Carlos Moyses
By organisation
Materials TheoryStructural Chemistry
In the same journal
The Journal of Physical Chemistry C
Atom and Molecular Physics and Optics

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 10 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf