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Florian Le Formal

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Related publications (38)

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A Ga2O3 underlayer as an isomorphic template for ultrathin hematite films toward efficient photoelectrochemical water splitting

Michael Graetzel, Kevin Sivula, Florian Le Formal, Nicolas Tétreault, Maurin Cornuz, Jérémie Minh-Châu Brillet, Takashi Hisatomi

Hematite photoanodes for photoelectrochemical (PEC) water splitting are often fabricated as extremely-thin films to minimize charge recombination because of the short diffusion lengths of photoexcited carriers. However, poor crystallinity caused by structu ...

2012

The Transient Photocurrent and Photovoltage Behavior of a Hematite Photoanode under Working Conditions and the Influence of Surface Treatments

Michael Graetzel, Kevin Sivula, Florian Le Formal

Hematite (alpha-Fe2O3) is widely recognized as a promising candidate for the production of solar fuels via water splitting, but its intrinsic optoelectronic properties have limited its performance to date. In particular, the large electrochemical overpoten ...

American Chemical Society2012

Iron-Rich Natural Mineral Gibeon Meteorite Catalyzed N -formylation of Amines using CO2 as the C1 Source

Paul Joseph Dyson, Arnaud Magrez, Kevin Sivula, Florian Le Formal, Aswin Gopakumar, Ismail Akçok

2018

Efficient suppression of back electron/hole recombination in cobalt phosphate surface-modified undoped bismuth vanadate photoanodes

Florian Le Formal

In this paper, we compared for the first time the dynamics of photogenerated holes in BiVO4 photoanodes with and without CoPi surface modification, employing transient absorption and photocurrent measurements on microsecond to second timescales. CoPi surfa ...

Royal Society of Chemistry2015

Insights into the interfacial carrier behaviour of copper ferrite ( CuFe2O4) photoanodes for solar water oxidation

Kevin Sivula, Liang Yao, Nestor Guijarro Carratala, Florian Le Formal, Yongpeng Liu, Florent Alexandre Boudoire

Designing efficient yet robust photoanodes for water oxidation stands out as a major bottleneck in the realization of a feasible photoelectrochemical tandem cell for solar water splitting. Spinel copper ferrite (CuFe2O4) has been recently reported as a pot ...

Royal Society of Chemistry2019

Solar hydrogen production with semiconductor metal oxides: new directions in experiment and theory

Michael Graetzel, Kevin Sivula, Florian Le Formal, Jérémie Minh-Châu Brillet

An overview of a collaborative experimental and theoretical effort toward efficient hydrogen production via photoelectrochemical splitting of water into di-hydrogen and di-oxygen is presented here. We present state-of-the-art experimental studies using hem ...

2012

Artificial Photosynthesis with Semiconductor-Liquid Junctions

Kevin Sivula, Nestor Guijarro Carratala, Florian Le Formal

Given the urgent need to develop a sustainable, carbon neutral energy storage system on a global scale, intense efforts are currently underway to advance the field of artificial photosynthesis: i.e. solar fuel engineering. In this review we give an overvie ...

Schweizerische Chemische Gesellschaft2015

Evaluating Charge Carrier Transport and Surface States in CuFeO

Kevin Sivula, Nestor Guijarro Carratala, Florian Le Formal, Xavier Adrian Jeanbourquin, Mathieu Steven Prévot, Wiktor Stefan Bourée

Interest in delafossite (CuFeO2) as a candidate p-type photocathode for photoelectrochemical (PEC) solar fuel production has recently been increasing, mainly due to its excellent stability in aqueous environments and favorable light absorption properties. ...

American Chemical Society2017

Cathodic shift in onset potential of solar oxygen evolution on hematite by 13-group oxide overlayers

Michael Graetzel, Kevin Sivula, Florian Le Formal, Nicolas Tétreault, Maurin Cornuz, Jérémie Minh-Châu Brillet, Takashi Hisatomi

The onset potential of photoelectrochemical water oxidation on ultrathin hematite was improved by up to 200 mV by the chemical bath deposition of 13-group oxides as overlayers. It is proposed that the corundum-type overlayers released lattice strain of the ...

2011

Ultrafast Charge Carrier Recombination and Trapping in Hematite Photoanodes under Applied Bias

Michael Graetzel, Florian Le Formal, Stanley David Tilley, Maurin Cornuz

Transient absorption spectroscopy on subpicosecond to second time scales is used to investigate photogenerated charge carrier recombination in Si-doped nanostructured hematite (alpha-Fe2O3) photoanodes as a function of applied bias. For unbiased hematite, ...

American Chemical Society2014

Influence of Plasmonic Au Nanoparticles on the Photoactivity of Fe2O3 Electrodes for Water Splitting

Michael Graetzel, Florian Le Formal

An experimental study of the influence of gold nanoparticles on a alpha-Fe2O3 photoanodes for photoelectrochemical water splitting is described. A relative enhancement in the water splitting efficiency at photon frequencies corresponding to the plasmon res ...

American Chemical Society2011

Spectroelectrochemical analysis of the mechanism of (photo)electrochemical hydrogen evolution at a catalytic interface

Michael Graetzel, Florian Le Formal, Matthew Thomas Mayer, Stanley David Tilley

Multi-electron heterogeneous catalysis is a pivotal element in the ( photo) electrochemical generation of solar fuels. However, mechanistic studies of these systems are difficult to elucidate by means of electrochemical methods alone. Here we report a spec ...

Springer Nature2017

Hematite photoelectrodes for water splitting: evaluation of the role of film thickness by impedance spectroscopy

Michael Graetzel, Kevin Sivula, Florian Le Formal

The electrochemical behavior of alpha-Fe2O3 photoelectrodes prepared by spray pyrolysis with different thicknesses was examined under dark and illumination conditions. The main charge transport phenomena occurring in the PEC cell photoelectrodes were chara ...

Royal Soc Chemistry2014

Robust Hierarchically Structured Biphasic Ambipolar Oxide Photoelectrodes for Light-Driven Chemical Regulation and Switchable Logic Applications

Kevin Sivula, Nestor Guijarro Carratala, Florian Le Formal, Xavier Adrian Jeanbourquin, Mathieu Steven Prévot, Melissa Catherine Olson, Wiktor Stefan Bourée

Tunable ambipolar photoelectrochemical behavior emerges from microdomains of nanostructured p-type CuFeO2 and n-type Fe2O3 that arise from a single facile solution-processed thin fi lm. The switchable operation of this system is controlled by chemical, opt ...

Wiley-Blackwell2016

Solid-State Dye-Sensitized Solar Cells using Ordered TiO2 Nanorods on Transparent Conductive Oxide as Photoanodes

Michael Graetzel, Shaik Mohammed Zakeeruddin, Robin Humphry-Baker, Mingkui Wang, Florian Le Formal, Soo-Jin Moon, Carole Graetzel

TiO2 nanorod arrays were prepared on top of a transparent conductive glass substrate covered with a thin TiO2 compact layer. Solid-state dye-sensitized solar cells (SSDSCs) were fabricated using these structured TiO2 films sensitized with C106 dye as a pho ...

American Chemical Society2012

Kinetics of Photoelectrochemical Oxidation of Methanol on Hematite Photoanodes

Michael Graetzel, Florian Le Formal, Matthew Thomas Mayer

The kinetics of photoelectrochemical (PEC) oxidation of methanol, as a model organic substrate, on alpha-Fe2O3 photoanodes are studied using photoinduced absorption spectroscopy and transient photocurrent measurements. Methanol is oxidized on alpha-Fe2O3 t ...

American Chemical Society2017

Enhanced-Light-Harvesting Amphiphilic Ruthenium Dye for Efficient Solid-State Dye-Sensitized Solar Cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Robin Humphry-Baker, Mingkui Wang, Peng Wang, Florian Le Formal, Soo-Jin Moon, Carole Graetzel

A ruthenium sensitizer (coded C101, NaRu (4,4'-bis(5-hexylthiophen-2-yl)-2,2'-bipyridine) (4-carboxylic acid-4'-caboxylate-2,2'-bipyridine) (NCS)(2)) containing a hexylthiophene-conjugated bipyridyl group as an ancillary ligand is presented for use in soli ...

Wiley-Blackwell2010

Evaluating spinel ferrites MFe2O4 (M = Cu, Mg, Zn) as photoanodes for solar water oxidation: prospects and limitations

Kevin Sivula, Nestor Guijarro Carratala, Florian Le Formal, Xiaoyun Yu, Xavier Adrian Jeanbourquin, Mathieu Steven Prévot, Pauline Bornoz, Melissa Catherine Olson

2018