Publications by Astrid Johana Olaya Avendano

Visible-light driven water oxidation and oxygen production at soft interfaces

Hubert Girault, Astrid Johana Olaya Avendano, Jorge Gustavo Uranga, Julieta Soledad Riva, Sara Natalia Moya Betancourt

The visible light driven water oxidation reaction (WOR) by the organic electron acceptor 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-quinodimethane (TCNQF(4)) was studied at the water|butyronitrile interface. The WOR was performed at neutral pH, and without any ...

Royal Society of Chemistry2022

Water photo-oxidation on self-assembled organic/Co3O4 metal junctions in biphasic systems

Hubert Girault, Astrid Johana Olaya Avendano, Julieta Soledad Riva

A microwater vertical bar butyronitrile (W vertical bar BCN) interface was used to study the effect of the interfacial chemical polarization on the efficiency of the visible-light induced water oxidation reaction (WOR) by the electron acceptor/ photosensit ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Visible-Light-Driven Water Oxidation on Self-Assembled Metal-Free Organic@Carbon Junctions at Neutral pH

Hubert Girault, Astrid Johana Olaya Avendano, Julieta Soledad Riva, Dominika Baster, Wanderson Oliveira Da Silva

Sustainable water oxidation requires low-cost, stable, and efficient redox couples, photosensitizers, and catalysts. Here, we introduce the in situ self-assembly of metal-atom-free organic-based semiconductive structures on the surface of carbon supports. ...

AMER CHEMICAL SOC2021

How to polarise an interface with ions: the discrete Helmholtz model

Hubert Girault, Astrid Johana Olaya Avendano, Grégoire Clément Gschwend

The distribution of electrolytes in an electric field usually relies on theories based on the Poisson-Boltzmann formalism. These models predict that, in the case of a metallic electrode, ionic charges screen the electrode potential, leading to concentratio ...

2020

Structure and reactivity of the polarised liquid–liquid interface: what we know and what we do not

Hubert Girault, Astrid Johana Olaya Avendano, Grégoire Clément Gschwend, Pekka Eero Peljo

Charge transfer phenomena at the interface between two immiscible electrolyte solutions (ITIES) are electrochemical reactions taking place in soft media. Owing to their liquid nature, the ITIES shows a large panel of electrochemical reactions including ele ...

2020

Standard ion transfer potential at the water|butyronitrile interface

Hubert Girault, Astrid Johana Olaya Avendano, Victor Costa Bassetto, Julieta Soledad Riva

Butyronitrile is an organic solvent stable enough to be used in photochemical reactions at liquid/liquid interfaces. However, it provides a rather short polarisation window making the analysis of ion transfer across the water|butyronitrile interface challe ...

2019

Two dimensional diffusion-controlled triplet–triplet annihilation kinetics

Pierre-François Marie Brevet, Hubert Girault, Astrid Johana Olaya Avendano, Grégoire Clément Gschwend, Morgan Kazmierczak

Diffusion controlled chemical reactions are usually observed in three dimensionalmedia. In contrast, planar bimolecular reactions taking place between reagents adsorbed at a soft interface are two-dimensional and therefore cannot be studied within the same ...

2019

A Self-Assembled Organic/Metal Junction for Water Photo-Oxidation

Hubert Girault, Astrid Johana Olaya Avendano, Natalia Gasilova, Jonnathan Cesar Hidalgo Acosta, Victor Costa Bassetto, Terumasa Omatsu, Julieta Soledad Riva

We report the in situ self-assembly of TTF, TTF•+, and BF4 − or PF6 − into p-type semiconductors on the surface of Pt microparticles dispersed in water/acetonitrile mixtures. The visible light photoactivation of these selfassemblies leads to water oxidatio ...

2019

Photosensitized Hydrogen Evolution on a Floating Electrocatalyst Coupled to Electrochemical Recycling

Hubert Girault, Astrid Johana Olaya Avendano, Jonnathan Cesar Hidalgo Acosta, Terumasa Omatsu

Photoexcited protonated tetrathiafulvalene (HTTF+) was found to act as a photosensitizer, injecting electrons into Pt microparticles (floating electrocatalysts) to produce H2 and TTF•+ in acidic acetonitrile. In addition, TTF•+ was electrochemically reduce ...

2018

Redox Electrocatalysis of Floating Nanoparticles: Determining Electrocatalytic Properties without the Influence of Solid Supports

Hubert Girault, Astrid Johana Olaya Avendano, Thomas James Stockmann, Micheal Diarmaid Scanlon, Pekka Eero Peljo, Evgeny Smirnov, Lucie Josette Renée Rivier

Redox electrocatalysis (catalysis of electron-transfer reactions by floating conductive particles) is discussed from the point-of-view of Fermi level equilibration, and an overall theoretical framework is given. Examples of redox electrocatalysis in soluti ...

2017

Chaotropic Agents Boosting the Performance of Photo-ionic Cells

Hubert Girault, Jelissa Risse, Manuel Alejandro Méndez Agudelo, Heron Vrubel, Astrid Johana Olaya Avendano, Pekka Eero Peljo, Romain Bourdon

Photo-ionic cells are a simple and scalable concept for direct solar energy storage, where the redox fuels produced by the photoreaction are separated in different phases to prevent recombination. The presence of chaotropic agents such as urea, that break ...

Amer Chemical Soc2015

Ultrafast Population Dynamics of Surface-Active Dyes during Electrochemically Controlled Ion Transfer across a Liquid|Liquid Interface

Pierre-François Marie Brevet, Hubert Girault, Astrid Johana Olaya Avendano, Evgeny Smirnov

We present for the first time experimental measurements on the ultrafast population dynamics of the model surface-active dye methyl orange (MO) during its ion transfer across the water|1,2-dichloroethane interface by using time-resolved surface second harm ...

Amer Chemical Soc2014

Interfacial Self-Assembly as Catalytic Platform for Multielectron Redox Reactions

Astrid Johana Olaya Avendano

In Nature, many vital biological processes take place across the interface formed between two dielectric media. For instance, photosynthesis and aerobic respiration involve a series of redox reactions occurring across energy-transducing membranes, in charg ...

EPFL2013

Photoinduced Biphasic Hydrogen Evolution: Decamethylosmocene as a Light-Driven Electron Donor

Hubert Girault, Imren Hatay, Heron Vrubel, Peiyu Ge, Astrid Johana Olaya Avendano, Micheal Diarmaid Scanlon

Excitation of the weak electron donor decamethylosmocene on illumination with white light produces an excited-state species capable of reducing organically solubilized protons under biphasic conditions. Insight into the mechanism and kinetics of light-driv ...

Wiley-Blackwell2013

Steady-state macroscale voltammetry in a supercritical carbon dioxide medium

Hubert Girault, Patrick Voyame, Astrid Johana Olaya Avendano, Dmitry Momotenko, Kathryn Ellen Toghill

The electrochemical oxidation and reduction of decamethylferrocene is demonstrated in supercritical carbon dioxide at a macro gold disc electrode at 100 bar and 313 K. Fast mass transport effects were exhibited and the corresponding steady-state voltammetr ...

Royal Soc Chemistry2013

Biphasic water splitting by osmocene

Hubert Girault, Anne-Clémence Corminboeuf, Xile Hu, Manuel Alejandro Méndez Agudelo, Imren Hatay, Heron Vrubel, Peiyu Ge, Astrid Johana Olaya Avendano

The photochemical reactivity of osmocene in a biphasic water-organic solvent system has been investigated to probe its water splitting properties. The photoreduction of aqueous protons to hydrogen under anaerobic conditions induced by osmocene dissolved in ...

National Academy of Sciences2012

Ion transfer across the water | trifluorotoluene interface

Hubert Girault, Peiyu Ge, Astrid Johana Olaya Avendano

This work introduces trifluorotoluene as an alternative organic solvent for studying charge transfer across liquid vertical bar liquid interfaces. In comparison with the most popular organic solvents in this field, 1,2-dichloroethane and nitrobenzene, trif ...

Elsevier2012

Interfacial Self-Assembly of Water-Soluble Cationic Porphyrins for the Reduction of Oxygen to Water

Pierre-François Marie Brevet, Hubert Girault, Astrid Johana Olaya Avendano

Meet at the border: Assembly of the water-soluble cobalt tetrakis(N-methylpyridinium-4-yl)porphyrin [CoTMPyP]4+ at soft interfaces is enhanced and stabilized by its interfacial interaction with the lipophilic anion (C6F5)4B−. The supramolecular structure t ...

Wiley-VCH Verlag GmbH2012

Four-electron oxygen reduction by Tetrathiafulvalene

Hubert Girault, Péter Kalman Péchy, Jérôme Florian Gonthier, Anne-Clémence Corminboeuf, Peiyu Ge, Astrid Johana Olaya Avendano

The four-electron reduction of oxygen by tetrathiafulvalene (TTF) in acidified 1,2-dichloroethane and at the acidified water/1,2-dichloroethane interface has been observed. Spectroscopy and ion transfer voltammetry results suggest that the reaction proceed ...

2011

Evaluation of Gibbs Energy of Dioxouranium Transfer at an Electrified Liquid vertical bar Liquid Interface Supported on a Microhole

Hubert Girault, Zhifeng Ding, Manuel Alejandro Méndez Agudelo, Astrid Johana Olaya Avendano, Thomas James Stockmann

Herein is reported the determination of the Gibbs energy of dioxouranium (UO22+) transfer across an interface between two immiscible electrolytic solutions (ITIES), water and 1,2-dichloroethane, that was supported at a 25 mu m diameter microhole, by means ...

2011