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Electron transfer dynamics in Quantum Dot based dyads and triads

Applicant Ruggi Albert
Number 159716
Funding scheme Project funding (Div. I-III)
Research institution Département de Chimie Université de Fribourg
Institution of higher education University of Fribourg - FR
Main discipline Inorganic Chemistry
Start/End 01.07.2015 - 30.06.2019
Approved amount 292'923.00
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Keywords (5)

transition metal complexes; electron transfer; dyads; artificial photosynthesis; Quantum Dots

Lay Summary (Italian)

Lead
Electron transfer dynamics in Quantum Dot based dyads and triadsDinamiche di trasferimento elettronico in diadi e triadi basate su Quantum Dots
Lay summary

In sintesi

Lo sviluppo di tecniche per l’ottenimento di energia da fonti rinnovabili ed ecologicamente sostenibili costituisce una delle priorità della ricerca scientifica. Un degli obiettivi più ambiziosi consiste nell’utilizzare la luce per produrre direttamente sostanze combustibili attraverso un processo che imita ciò che avviene nelle piante: la Fotosintesi Artificiale.

 Soggetto e obiettivo

Obiettivo di questo progetto è l’investigazione di sistemi basati su semiconduttori nanometrici (Quantum Dots). Essi, analogamente alla clorofilla nelle piante, assorbono la luce e ne trasferiscono l’energia sotto forma di elettroni. Gli elettroni attivano poi complessi metallici che catalizzano le due reazioni del processo di scissione dell’acqua in idrogeno e ossigeno. Scopo di questa ricerca è la comprensione a livello molecolare e l’ottimizzazione dei cambiamenti che avvengono in seguito all’assorbimento della luce, ossia la dinamica dei trasferimenti elettronici. Alla fine di questo progetto di ricerca, disporremo di informazioni cruciali per contribuire alla progettazione di sistemi capaci di scindere l’acqua in idrogeno e ossigeno utilizzando la luce come fonte di energia.

 Contesto socio-scientifico

  Nel 2011 il Consiglio Federale svizzero ha deciso di abbandonare progressivamente la produzione di energia nucleare, procedendo ad un riorientamento della politica energetica ed investendo  nel settore delle energie alternative. La realizzazione della Fotosintesi Artificiale resta tuttora una sfida formidabile per la ricerca scientifica. Questo progetto si inquadra in tale contesto e mira a fornire un contributo alla realizzazione di un sistema capace di utilizzare l’energia solare per ottenere idrogeno a partire dall’acqua.

Direct link to Lay Summary Last update: 02.04.2015

Responsible applicant and co-applicants

Employees

Name Institute

Publications

Publication
Heptacoordinate Co(II) Catalyst for Light-driven Hydrogen Production in Fully Aqueous Medium
LucariniFiorella, RuggiAlbert (2018), Heptacoordinate Co(II) Catalyst for Light-driven Hydrogen Production in Fully Aqueous Medium, in Chimia, 72(4), 203-206.
Heptacoordinate CoII Complex: A New Architecture for Photochemical Hydrogen Production
Lucarini Fiorella, Pastore Mariachiara, Vasylevskyi Serhii, Varisco Massimo, Solari Euro, Crochet Aurelien, Fromm Katharina M., Zobi Fabio, Albert Ruggi (2017), Heptacoordinate CoII Complex: A New Architecture for Photochemical Hydrogen Production, in Chemistry-A European Journal, 23(28), 6768-6771.

Collaboration

Group / person Country
Types of collaboration
Dr. Mirco Natali Italy (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Dr. Marco Morazzi Spain (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Dr. Vincent Artero France (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Exchange of personnel
Dr. Rosario Scopellit France (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Dr. Mariachiara Pastore France (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication

Awards

Title Year
SCS-Metrohm Award for the best oral presentation in Inorganic and Coordination Chemistry (runner up) 2017

Abstract

The development of technologies aimed to produce fuels from widely available sources in an economic and sustainable way is one of the most important scientific challenges of XXI century, considering the economical impact of the current raise of energy demand and the environmental effects deriving from the massive use of fossil fuels. Amongst the traditional strategies currently used to produce green energy from renewable sources, the possibility of obtaining a highly energetic and environmental friendly fuel like hydrogen using sunlight and water as starting sources would have an enormous impact on the everyday life. A system capable of realising water splitting by using sunlight has been the “Holy Grail” of scientific research for at least three decades. Semiconductor Quantum Dots have recently been object of a growing attention for application in solar cells and optoelectronic devices, due to their bright performances in terms of light absorption and photostability. However, only a very few system based on Quantum Dots have been reported so far in the field of artificial photosynthesis and in most cases such systems have been only poorly characterised in terms of electron transfer dynamics. Here we propose a new approach based on a family of dyads and triads containing a semiconductor Quantum Dot as sensitizer and transition metals-based catalysts. The objectives of this proposal can be summarized as follows:1) Synthesis of dyads containing oxidising moieties based on Ir(III) and Fe(II) complexes functionalised with spacers of different length and chemical nature and with a dithiocarbamate connecting unit. 2) Synthesis of dyads containing reducing moieties based on Co(III) and Co(II) complexes functionalised with spacers of different length and chemical nature and with a dithiocarbamate connecting unit.3) Synthesis of triads containing oxidation and reducing moieties connected to a rigid scaffold. 4) In-depth study of the photophysical properties of such dyads and triads, with special attention to the electron/hole transfer dynamics taking place between the Quantum Dot (sensitizer) and the metal complexes (photocatalysts) aimed at the realization of an optimised integrated system for water splitting.Compared to the systems so far realized in this field, our strategy shows several advantages: • Semiconductor Quantum Dots show high photostability (in the presence of suitable capping units) and high molar extinction coefficients, thus they are ideal light harvesting units.• Transition metal complexes can be attached to the Quantum Dots surface by dithiocarbamate functional groups, which can be easily prepared starting from primary amines. • The modularity of the system enables to optimise separately the two catalytic moieties.• The study of the electron transfer mechanisms in dyads will enable us to develop a strategy to avoid back-electron transfer upon induction of a kinetic-controlled unidirectional electron transfer in triads. We argue that the research presented in this proposal represents a major step towards the definition of a straightforward method for the realization of integrated systems (triads) for light-driven water splitting. Besides the evident impact of such systems on the everyday life, the in-depth investigation of the photoinduced electron transfer process is expected to give a remarkable contribution to the photochemical research in the field of artificial photosynthesis.
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