Acid-triggering of light-induced charge-separation in hybrid organic/inorganic molecular photoactive dyads for harnessing solar energy

Research output: Contribution to journalArticle

Abstract

H+ modulated charge-transfer in photoexcited covalent polyoxometalate-bodipy conjugates is described. The hybrid organic/inorganic molecular photoactive dyads are based on Keggin-type polyoxometalates (POMs, where KM = [PM11O39] and M = Mo or W) covalently grafted via an organotin linker to a bodipy (BOD) photosensitizer. The relative potentials of the photosensitizer and POM are aligned such that light-induced electron transfer from BOD to POM is permitted for the polyoxomolybdate KMoSn[BOD] but not effective for the polyoxotungstate analogue KWSn[BOD]. In both cases, the addition of acid shifts the redox potential of the POM only, to increase the driving force for electron transfer. This leads to charge-separation being switched on for KWSn[BOD] in the presence of acid. The addition of acid to KMoSn[BOD] accelerates charge-separation by an order of magnitude (from 2 ns to 200 ps) and is accompanied by a deceleration of charge recombination, leading to a charge-separated state lifetime of up to 1.3 μs. This behaviour is consistent with proton coupled electron transfer, which has previously been observed electrochemically for POMs, but this study shows, for the first time, the impact of protonation on photoinduced electron transfer. This journal is

Details

Authors
  • Elisabetta Benazzi
  • Joshua Karlsson
  • Youssef Ben M'Barek
  • Pavel Chabera
  • Sébastien Blanchard
  • Sandra Alves
  • Anna Proust
  • Tönu Pullerits
  • Guillaume Izzet
  • Elizabeth A. Gibson
Organisations
External organisations
  • University of Newcastle upon Tyne
  • Pierre and Marie Curie University
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Physical Chemistry
Original languageEnglish
Pages (from-to)1610-1618
Number of pages9
JournalInorganic Chemistry Frontiers
Volume8
Issue number6
Publication statusPublished - 2021
Publication categoryResearch
Peer-reviewedYes