Publications de Kevin Sivula | EPFL Graph Search

Publications associées (160)

Nanocrystalline Boron-Doped Diamond as a Corrosion-Resistant Anode for Water Oxidation via Si Photoelectrodes

Kevin Sivula, Jun Ho Yum, Ladislav Kavan, Florian Le Formal

Due to its high sensitivity to corrosion, the use of Si in direct photoelectrochemical (PEC) water-splitting systems that convert solar energy into chemical fuels has been greatly limited. Therefore, the development of low-cost materials resistant to corro ...

AMER CHEMICAL SOC2018

Influence of Composition on Performance in Metallic Iron-Nickel-Cobalt Ternary Anodes for Alkaline Water Electrolysis

Lucas Yerly, Andreas Züttel, Kevin Sivula, Nestor Guijarro Carratala, Florent Alexandre Boudoire, Elizaveta Potapova Mensi

Metallic electrodes based on iron, nickel, and/or cobalt have re-emerged as promising cost-effective anodes for the alkaline oxygen evolution reaction (OER) due to their simplicity and their in situ formation of a highly active oxy-hydroxide surface cataly ...

AMER CHEMICAL SOC2020

Evolution of an Oxygen Near-Edge X-ray Absorption Fine Structure Transition in the Upper Hubbard Band in alpha-Fe2O3 upon Electrochemical Oxidation

Michael Graetzel, Kevin Sivula

Electrochemical oxidation of hematite (alpha-Fe2O3) nanoparticulate films at 600 mV vs Ag+/AgCl in KOH electrolyte forms a species at the hematite surface which causes a new transition in the upper Hubbard band between the Fe(3d)-O(2p) state region and the ...

American Chemical Society2011

High Performance Semiconducting Nanosheets via a Scalable Powder-Based Electrochemical Exfoliation Technique

Kevin Sivula, Aleksandra Radenovic, Victor Carle Adrien Boureau, Miao Zhang, Tzu-Heng Chen

The liquid-phase exfoliation of semiconducting transition metal dichalcogenide (TMD) powders into 2D nanosheets represents a promising route toward the scalable production of ultrathin high-performance optoelectronic devices. However, the harsh conditions ...

2022

Transparent Porous Conductive Substrates for Gas-Phase Photoelectrochemical Hydrogen Production

Kevin Sivula, Jun Ho Yum, Simon Nussbaum, Rebekah Anne Wells, Marina Caroline Michèle Caretti, Hannah Elizabeth Johnson, Emeline Cécile Rideau, Benjamin Goldman, Elizaveta Potapova Mensi

Gas diffusion electrodes are essential components of common fuel and electrolysis cells but are typically made from graphitic carbon or metallic materials, which do not allow light transmittance and thus limit the development of gas-phase based photoelectr ...

Wiley-V C H Verlag Gmbh2023

Activation Energies for the Rate-Limiting Step in Water Photooxidation by Nanostructured alpha-Fe2O3 and TiO2

Michael Graetzel, Kevin Sivula

Competition between charge recombination and the forward reactions required for water splitting limits the efficiency of metal-oxide photocatalysts. A key requirement for the photochemical oxidation of water on both nanostructured alpha-Fe2O3 and TiO2 is t ...

2011

Assembling a Photoactive 2D Puzzle: From Bulk Powder to Large- Area Films of Semiconducting Transition-Metal Dichalcogenide Nanosheets

Kevin Sivula, Rebekah Anne Wells

CONSPECTUS: Two-dimensional (2D) semiconducting materials are poised to revolutionize ultrathin, high-performance optoelectronic devices. In particular, transition-metal dichalcogenides (TMDs) are well-suited for applications requiring robust and stable ma ...

2023

Photoelectrochemical Water Splitting with Mesoporous Hematite Prepared by a Solution-Based Colloidal Approach

Michael Graetzel, Kevin Sivula, Florian Le Formal

Sustainable hydrogen production through photoelectrochemical water splitting using hematite (alpha-Fe2O3) is a promising approach for the chemical storage of solar energy, but is complicated by the material's nonoptimal optoelectronic properties. Nanostruc ...

American Chemical Society2010

Edge-Sharing Octahedrally Coordinated Ni-Fe Dual Active Sites on ZnFe2O4 for Photoelectrochemical Water Oxidation

Kevin Sivula

The structural properties of octahedral sites (B-Oh) in spinel oxides (AB(2)O(4)) play vital roles in the electrochemical performance of oxygen-related reactions. However, the precise manipulation of AB(2)O(4) remains challenging due to the complexity of t ...

WILEY2023

Multiarm and Substituent Effects on Charge Transport of Organic Hole Transport Materials

Mohammad Khaja Nazeeruddin, Kevin Sivula, Liang Yao, Antonio Prlj, Kun-Han Lin, Nikita Drigo, Han-Hee Cho

We explore several potential dopant-free triphenylamine-based hole transport materials for perovskite solar cells by combining two design strategies: (1) incorporation of multiple arms for mobility enhancement and (2) including Lewis bases that assist in d ...

2019

Assessing the Charge Carrier Dynamics at Hybrid Interfaces of Organic Photoanodes for Solar Fuels

Kevin Sivula, Yongpeng Liu, Han-Hee Cho

Organic semiconductors (OSCs) have emerged as promising active layers for photoanodes to drive photoelectrochemical (PEC) oxidation reactions. Interfacing an OSC with an inorganic electron transport layer (ETL) is key to enabling both high performance and ...

Amer Chemical Soc2024

Understanding Surface Recombination Processes Using Intensity-Modulated Photovoltage Spectroscopy on Hematite Photoanodes for Solar Water Splitting

Kevin Sivula, Nestor Guijarro Carratala, Yongpeng Liu

Converting solar energy into hydrogen through photoelectrochemical (PEC) water splitting offers a promising route towards a fully renewable energy economy. A fundamental understanding of photogenerated charge recombination processes in semiconducting photo ...

WILEY-V C H VERLAG GMBH2020

Controlling Photoactivity in Ultrathin Hematite Films for Solar Water-Splitting

Michael Graetzel, Kevin Sivula, Florian Le Formal

A promising route to increase the performance of hematite (alpha-Fe2O3) photoelectrodes for solar hydrogen production through water-splitting is to use an extremely thin layer of this visible light absorber on a nanostructured scaffold. However, the typica ...

Wiley-Blackwell2010

Photoelectrochemical CO2 Reduction at a Direct CuInGaS2/Electrolyte Junction

Michael Graetzel, Kevin Sivula, Jun Ho Yum, Nestor Guijarro Carratala, Dan Ren, Yongpeng Liu, Meng Xia, Simon Nussbaum

Photoelectrochemical (PEC) CO2 reduction has received considerable attention given the inherent sustainability and simplicity of directly converting solar energy into carbonbased chemical fuels. However, complex photocathode architectures with protecting l ...

AMER CHEMICAL SOC2023

WO3-Fe2O3 Photoanodes for Water Splitting: A Host Scaffold, Guest Absorber Approach

Michael Graetzel, Kevin Sivula, Florian Le Formal

Solar hydrogen production via watersplitting with hematite (Fe2O3) has been limited by poor light absorption and a small hole diffusion length. These drawbacks can be overcome by using a high-surface-area host to support a thin layer of hematite-allowing p ...

2009

Bulk Heterojunction Organic Semiconductor Photoanodes: Tuning Energy Levels to Optimize Electron Injection

Kevin Sivula, Jun Ho Yum, Liang Yao, Nestor Guijarro Carratala, Yongpeng Liu, Arvindh Sekar, Han-Hee Cho, Juan Manuel Moreno Naranjo, Barbara Alexandra Primera Darwich

The use of a bulk heterojunction of organic semiconductors to drive photoelectrochemical water splitting is an emerging trend; however, the optimum energy levels of the donor and acceptor have not been established for photoanode operation with respect to e ...

AMER CHEMICAL SOC2022

Supramolecular interactions using β-cyclodextrin in controlling perovskite solar cell performance

Parnian Ferdowsi, Kevin Sivula, Jun Ho Yum, Jiyoun Seo

In the context of perovskite solar cells (PSCs), enhancing device performance often involves adding a small excess of lead iodide (PbI2) to the precursor solution. However, the presence of unreacted PbI2 can lead to accelerated degradation compromising lon ...

Royal Society of Chemistry2024

Robust Electron Transport Layers via In Situ Cross-Linking of Perylene Diimide and Fullerene for Perovskite Solar Cells

Kevin Sivula, Jun Ho Yum, Liang Yao, Sylvain Nicolay, Soo-Jin Moon, Marina Caroline Michèle Caretti

While employing charge transport layers (CTLs) in optoelectronic devices including hybrid perovskite solar cells is essential for high performance, using solution-processed organic semiconductor-based CTLs poses challenges for device fabrication. Cross-lin ...

2019

A halted photodeposition technique controls co-catalyst loading and morphology on organic semiconductor nanoparticles for solar H 2 production

Kevin Sivula, Victor Carle Adrien Boureau, Colin Jeanguenat, Connor Robert Firth

Solar hydrogen production with semiconductor photocatalyst particles typically requires co-catalysts to accelerate the hydrogen evolution reaction, but since co-catalysts are often deposited in situ, the rate of their nucleation/growth and role in parasiti ...

Wiley2024

Highly active oxide photocathode for photoelectrochemical water reduction

Michael Graetzel, Kevin Sivula, Vincent Laporte, Adriana Paracchino

A clean and efficient way to overcome the limited supply of fossil fuels and the greenhouse effect is the production of hydrogen fuel from sunlight and water through the semiconductor/water junction of a photoelectrochemical cell, where energy collection a ...

Nature Publishing Group2011