Publications by Haiqiang Deng | EPFL Graph Search

Electrochemical Dynamics of a Single Platinum Nanoparticle Collision Event for the Hydrogen Evolution Reaction

Chronoamperometry was used to study the dynamics of Pt nanoparticle (NP) collision with an inert ultramicroelectrode via electrocatalytic amplification (ECA) towards hydrogen evolution reaction. First, ECA and dynamic light scattering (DLS) results reveal ...

Wiley-VCH Verlag GmbH2018

Single Organic Droplet Collision Voltammogram via Electron Transfer Coupled Ion Transfer

Haiqiang Deng, Pekka Eero Peljo, Cheng Liu

Single-emulsion toluene oil droplets (femtoliter) containing a hydrophobic redox probe that are dispersed in water stochastically collide with an ultramicroelectrode (UME). The fast-scan cyclic voltammetry (FSCV) or Fourier-transformed sinusoidal voltammet ...

American Chemical Society2017

Oxygen Reduction at Soft Interfaces Catalyzed by In Situ-Generated Reduced Graphene Oxide

Hubert Girault, Fernando Cortes Salazar, Véronique Amstutz, Haiqiang Deng, Micheal Diarmaid Scanlon

Face to face: Flakes of reduced graphene oxide, synthesized in situ at the liquid/liquid interface from a graphene-oxide precursor, are capable of catalyzing the biphasic reduction of protons to hydrogen peroxide in the presence of molecular oxygen and an ...

Wiley-V C H Verlag Gmbh2014

Electrochemical oxygen reduction at soft interfaces catalyzed by the transfer of hydrated lithium cations

Hubert Girault, Haiqiang Deng, Thomas James Stockmann, Pekka Eero Peljo

The oxygen reduction reaction by decamethylferrocene (DMFc), triggered by hydrophilic metallic cations behaving as Lewis acids towards water molecules in a homogeneous organic phase reaction, was investigated using cyclic voltammetry at the water|1,2-dichl ...

Elsevier2014

Oxygen Reduction at Soft Interfaces

Haiqiang Deng

EPFL2014

Surprising acidity of hydrated lithium cations in organic solvents

Hubert Girault, Liang Qiao, Haiqiang Deng, Thomas James Stockmann, Pekka Eero Peljo

Lithium cations are shown to have a significant role on catalyzing oxygen and proton reduction along with SN1 reactions in biphasic systems. We propose that this catalytic effect is due to the surprising acidity of the hydrated cations; interactions betwee ...

Royal Society of Chemistry2014

Kinetic differentiation of bulk/interfacial oxygen reduction mechanisms at/near liquid/liquid interfaces using scanning electrochemical microscopy

Hubert Girault, Fernando Cortes Salazar, Dmitry Momotenko, Haiqiang Deng, Thomas James Stockmann, Pekka Eero Peljo

The present work describes the application of scanning electrochemical microscopy (SECM) in the feedback mode to determine the kinetics of oxygen reduction at or near the liquid/liquid interface – between water and 1,2-dichloroethane (w/DCE). The system co ...

Elsevier2014

Mechanism of oxygen reduction by metallocenes near liquid|liquid interfaces

Hubert Girault, Haiqiang Deng, Thomas James Stockmann, Pekka Eero Peljo

The mechanism of the oxygen reduction reaction (ORR) at a liquid|liquid interface, employing ferrocene (Fc) derivatives – such as decamethylferrocene (DMFc) – as a lipophilic electron donor along with sulfuric acid as an aqueous proton source, was elucidat ...

Elsevier2014

Conductive Gold Nanoparticle Mirrors at Liquid/Liquid Interfaces

Hubert Girault, Frédéric Gumy, Carlos Manuel De Melo Pereira, Fernando Cortes Salazar, Véronique Amstutz, Dmitry Momotenko, Haiqiang Deng, Pingping Fang, Micheal Diarmaid Scanlon

Gold nanoparticle (Au NP) mirrors, that exhibit both high reflectance and electrical conductance, were self-assembled at a [heptane + 1,2-dichloroethane]/water liquid/liquid interface. The highest reflectance, as observed experimentally and confirmed by fi ...

Amer Chemical Soc2013

Parylene C Coated Microelectrodes For Scanning Electrochemical Microscopy

Hubert Girault, Carlos Manuel De Melo Pereira, Fernando Cortes Salazar, Haiqiang Deng, Pekka Eero Peljo

Herein, we present a simple microelectrode preparation methodology consisting in coating a platinum wire or a carbon fiber with a thin insulating Parylene C film (e.g. 1–10 μm), to produce SECM probes with a small and constant probe RG (i.e. ratio between ...

Elsevier2013

Oxygen and hydrogen peroxide reduction by 1,2-diferrocenylethane at a liquid/liquid interface

Hubert Girault, Fernando Cortes Salazar, Peiyu Ge, Haiqiang Deng, Pekka Eero Peljo

Molecular oxygen and hydrogen peroxide reduction by 1,2-diferrocenylethane (DFcE) was investigated at a polarized water/1,2-dichloroethane (W/DCE) interface. The overall reaction points to a proton-coupled electron transfer (PCET) mechanism, where the firs ...

Elsevier2012

Artificial Photosynthesis at Soft Interfaces

Hubert Girault, Patrick Voyame, Fernando Cortes Salazar, Manuel Alejandro Méndez Agudelo, Imren Hatay, Peiyu Ge, Astrid Johana Olaya Avendano, Haiqiang Deng, Zahra Nazemi

The concept of artificial photosynthesis at a polarised liquid membrane is presented. It includes two photosystems, one at each interface for the hydrogen and oxygen evolution respectively. Both reactions involve proton coupled electron transfer reactions, ...

Schweizerische Chemische Gesellschaft2011