Picosecond Optical Switching Based on Biphotonic Excitation of an Electron Donor-Acceptor-Donor Molecule

O’Neil, Michael; Niemczyk, Mark P.; Svec, Walter A.; Gosztola, David J.; Gaines, George L.; Wasielewski, Michael R.

doi:10.1126/science.257.5066.63

Cited by 403 publications

(253 citation statements)

References 25 publications

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“…25 However, only a few molecular photoactive systems with a designed charge accumulation site have been described so far. [26][27][28][29][30] Another requirement is crucial for efficient charge accumulation in such systems: when partially filled, the reservoir should not interfere with the photoactive moiety. Indeed, in classical donor-acceptor (D-A) systems, the electron acceptor, once reduced, potentially becomes an electron donor and often displays lightabsorbing properties.…”

mentioning

confidence: 99%

Charge photo-accumulation and photocatalytic hydrogen evolution under visible light at an iridium(iii)-photosensitized polyoxotungstate

Matt

Fize

Moussa

et al. 2013

Energy Environ. Sci.

148

115

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Steady-state irradiation under visible light of a covalent Ir(III)-photosensitized polyoxotungstate is reported. In the presence of a sacrificial electron donor, the photolysis leads to the very efficient photoreduction of the polyoxometalate. Successive formation of the one-electron and two-electron reduced species, which are unambiguously identified by comparison with spectroelectrochemical measurements, is observed with a significantly faster rate reaction for the formation of the oneelectron reduced species. The kinetics of the photoreduction, which are correlated to the reduction potentials of the polyoxometalate (POM), can be finely tuned by the presence of an acid. Indeed light-driven formation of the two-electron reduced POM is considerably facilitated in the presence of acetic acid. The system is also able to perform photocatalytic hydrogen production under visible light without significant loss of performance over more than 1 week of continuous photolysis and displays higher photocatalytic efficiency than the related multi-component system, outlining the decisive effect of the covalent bonding between the POM and the photosensitizer. This functional and modular system constitutes a promising step for the development of charge photoaccumulation devices and subsequent photoelectrocatalysts for artificial photosynthesis.Photoconversion of light into chemical fuels is emerging as a major scientific challenge. [1][2][3][4] In the past decades, molecular approaches have mostly focused on one hand on the design of photosensitive systems displaying long-lived photo-induced charge separation states to permit further electron transfers 5-10 and, on the other hand, on catalysts able to use these photogenerated charges for achieving either oxygen [11][12][13][14][15][16][17][18] or hydrogen evolution. [19][20][21][22][23][24] As these two reactions are multi-electronic processes while photosensitizers deliver electrons and holes sequentially, the charges need to be directed to a charge accumulation site. 25 However, only a few molecular photoactive systems with a designed charge accumulation site have been described so far. [26][27][28][29][30] Another requirement is crucial for efficient charge accumulation in such systems: when partially filled, the reservoir should not interfere with the photoactive moiety. Indeed, in classical donor-acceptor (D-A) systems, the electron acceptor, once reduced, potentially becomes an electron donor and often displays lightabsorbing properties. Thus it may act, in a subsequent light-driven process, as a deleterious 47,48 In the previously mentioned study, transient absorptions measurements only allowed for the characterization of the first photo-induced electron transfer. Charge photo-accumulation studies can be achieved in the presence of an additional electron donor in the solution that can irreversibly quench the charge separation state, regenerate the initial state of the photosensitizer and make a second photo-induced process possible. We herein provide unprecedente...

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confidence: 99%

Charge photo-accumulation and photocatalytic hydrogen evolution under visible light at an iridium(iii)-photosensitized polyoxotungstate

Matt

Fize

Moussa

et al. 2013

Energy Environ. Sci.

148

115

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“…[1][2][3] Water splitting, viewed as the sum of the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), represents one of the most promising, yet challenging, options in this regard.…”

Section: Introductionmentioning

confidence: 99%

Boosting water oxidation layer-by-layer

Hidalgo-Acosta

Scanlon

Méndez

et al. 2016

Phys. Chem. Chem. Phys.

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), moving from acidic to alkaline conditions. Bulk electrolysis experiments revealed that the IrO 2 /PDDA films were stable and adherent under acidic and neutral conditions but degraded in alkaline solutions. Oxygen was evolved with Faradaic efficiencies approaching 100% under acidic (pH 1) and neutral (pH 7) conditions, and 88% in alkaline solutions (pH 13).This layer-by-layer approach forms the basis of future large-scale OER electrode development using ink-jet printing technology.

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“…5a). [32] When using low excitation densities, one detects primarily the P + -PBDCI --P photoproduct by picosecond transient absorption spectroscopy. However, when increasing the laser excitation density above 5 photons per molecule, the lifetime of this photoproduct markedly decreases and the characteristic spectroscopic signature of two-electron reduced PBDCI can be detected.…”

Section: A Few Specific Case Studies Of Photoinduced Charge Accumulationmentioning

confidence: 99%

Photoinduced Charge Accumulation in Molecular Systems

Bonn

Wenger²

2015

Chimia

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Fuel-forming reactions such as CO 2 reduction or water splitting require multiple redox equivalents. When aiming at light-driven production of energy-rich chemicals, nowadays often referred to as solar fuels, it therefore becomes important to master the photoinduced accumulation of electrons or holes on individual molecular components. Featured in this short review are some of the key molecular systems explored in this emerging field of research. This includes for example a trinuclear Ru(ii)-Rh(iii)-Ru(iii) complex or an Ir(iii)-sensitized polyoxotungstate hybrid, but also several systems in which electron or hole collection occurs at organic moieties such as perylenebis(dicarboximide), quinone-containing or oligotriarylamine-based units. In many cases the photodriven accumulation of charge requires the use of sacrificial electron donors, but there exist also a handful of studies in which redox equivalents can be accumulated without the use of such additives.

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Picosecond Optical Switching Based on Biphotonic Excitation of an Electron Donor-Acceptor-Donor Molecule

Cited by 403 publications

References 25 publications

Charge photo-accumulation and photocatalytic hydrogen evolution under visible light at an iridium(iii)-photosensitized polyoxotungstate

Charge photo-accumulation and photocatalytic hydrogen evolution under visible light at an iridium(iii)-photosensitized polyoxotungstate

Boosting water oxidation layer-by-layer

Photoinduced Charge Accumulation in Molecular Systems

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