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Yongpeng Liu

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Related publications (28)

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Novel Interfacial Characterization and Surface Engineering in Semiconductor Electrodes for Optimized Solar Fuel Production

Yongpeng Liu

Harvesting sunlight, the ultimate renewable power source, in a cost-effective way has been long recognized as a necessary route to meet the global energy challenges. Solar energy can be transformed into electricity by means of photovoltaic devices to suppl ...

EPFL2021

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

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

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

Hematite Photoanodes for Solar Water Splitting: A Detailed Spectroelectrochemical Analysis on the pH-Dependent Performance

Nestor Guijarro Carratala, Florian Le Formal, Yongpeng Liu, Florent Alexandre Boudoire

The effect of the electrolyte pH on the performance of metal oxide photoanodes for solar water oxidation has not been fully resolved, and contrasting views have been presented in recent reports. Herein, a comprehensive set of spectroelectrochemical techniq ...

AMER CHEMICAL SOC2019

MIL-101(Fe)/g-C3N4 for enhanced visible-light-driven photocatalysis toward simultaneous reduction of Cr(VI) and oxidation of bisphenol A in aqueous media

Kevin Sivula, Nestor Guijarro Carratala, Yongpeng Liu

Heterostructured composites with an excellent photocatalytic activity have attracted increasing attention because of their great application in environmental remediation. Herein, a MIL-101(Fe)/g-C3N4 heterojunction was synthesized via in-situ growth of MIL ...

ELSEVIER2020

A hybrid bulk-heterojunction photoanode for direct solar-to-chemical conversion dagger

Michael Graetzel, Kevin Sivula, Jun Ho Yum, Liang Yao, Nestor Guijarro Carratala, Dan Ren, Yongpeng Liu, Meng Xia, Arvindh Sekar, Rebekah Anne Wells, Han-Hee Cho, Barbara Alexandra Primera Darwich

Organic semiconductors (OSs) are emerging candidates as light-harvesting materials in photoelectrochemical (PEC) cells for direct solar-to-chemical conversion. Despite significant recent progress with OS-based photocathodes, the development of efficient an ...

ROYAL SOC CHEMISTRY2021

Identifying Reactive Sites and Surface Traps in Chalcopyrite Photocathodes

Michael Graetzel, Kevin Sivula, Liang Yao, Mounir Driss Mensi, Nestor Guijarro Carratala, Yongpeng Liu, Meng Xia

Gathering information on the atomic nature of reactive sites and trap states is key to fine tuning catalysis and suppressing deleterious surface voltage losses in photoelectrochemical technologies. Here, spectroelectrochemical and computational methods wer ...

Wiley-VCH Verlag GmbH2021

Efficient Cu2O Photocathodes for Aqueous Photoelectrochemical CO2 Reduction to Formate and Syngas

Michael Graetzel, Shaik Mohammed Zakeeruddin, Kevin Sivula, Mounir Driss Mensi, Dan Ren, Yongpeng Liu, Jing Gao, Linfeng Pan, Jun Li, Meng Xia

Photoelectrochemical carbon dioxide reduction (PEC-CO2R) represents a promising approach for producing renewable fuels and chemicals using solar energy. However, attaining even modest solar-to-fuel (STF) conversion efficiency often necessitates the use of ...

Amer Chemical Soc2023

A Direct Z-Scheme for the Photocatalytic Hydrogen Production from a Water Ethanol Mixture on CoTiO3/TiO2 Heterostructures

Kevin Sivula, Liang Yao, Nestor Guijarro Carratala, Yongpeng Liu

Photocatalytic H-2 evolution from ethanol dehydrogenation is a convenient strategy to store solar energy in a highly valuable fuel with potential zero net CO2 balance. Herein, we report on the synthesis of CoTiO3/TiO2 composite catalysts with controlled am ...

AMER CHEMICAL SOC2021

Establishing Stability in Organic Semiconductor Photocathodes for Solar Hydrogen Production

Kevin Sivula, Jun Ho Yum, Liang Yao, Nestor Guijarro Carratala, Florian Le Formal, Yongpeng Liu, Florent Alexandre Boudoire, Muhammad Aiman Bin Rahmanudin Hamdan, Arvindh Sekar, Rebekah Anne Wells, Han-Hee Cho

As organic semiconductors attract increasing attention to application in the fields of bioelectronics and artificial photosynthesis, understanding the factors that determine their robust operation in direct contact with aqueous electrolytes becomes a criti ...

AMER CHEMICAL SOC2020

Key factors boosting the performance of planar ZnFe2O4 photoanodes for solar water oxidation

Kevin Sivula, Nestor Guijarro Carratala, Yongpeng Liu, Florent Alexandre Boudoire

The performance of ZnFe2O4 photoanodes largely depends on their nanostructure, crystallinity and n-type doping, though decoupling their impact on photoactivity remains a challenge. Herein, the combined effects of the synthesis temperature and reductive ann ...

Royal Society of Chemistry2021

Understanding and Mitigating the Degradation of Perovskite Solar Cells Based on a Nickel Oxide Hole Transport Material during Damp Heat Testing

Christophe Ballif, Kevin Sivula, Jun Ho Yum, Mounir Driss Mensi, Yongpeng Liu, Christian Michael Wolff, Marion Solange Madeleine Dussouillez

The development of stable materials, processable on alarge area,is a prerequisite for perovskite industrialization. Beyond the perovskiteabsorber itself, this should also guide the development of all otherlayers in the solar cell. In this regard, the use o ...

AMER CHEMICAL SOC2023

Spray Synthesis of CuFeO2 Photocathodes and In-Operando Assessment of Charge Carrier Recombination

Kevin Sivula, Nestor Guijarro Carratala, Florian Le Formal, Yongpeng Liu, Florent Alexandre Boudoire, Charles Roger Jean Lhermitte

Semiconducting delafossite-phase CuFeO2 is a promising photocathode material for solar-driven hydrogen production given its suitable energy levels and established robustness for photoelectrochemical water reduction. Nevertheless, reported methods for prepa ...

AMER CHEMICAL SOC2021

Manufacturing with light - micro-assembly of opto-electronic microstructures

Yongpeng Liu

Optical micromanipulation allows the movement and patterning of discrete micro-particles within a liquid environment. However, for manufacturing applications it is desirable to remove the liquid, leaving the patterned particles in place. In this work, we h ...

Optical Soc Amer2017

Lead Halide Perovskite Quantum Dots to Enhance the Power Conversion Efficiency of Organic Solar Cells

Kevin Sivula, Jun Ho Yum, Liang Yao, Nestor Guijarro Carratala, Florian Le Formal, Yongpeng Liu, Rebekah Anne Wells, Han-Hee Cho, Barbara Alexandra Primera Darwich, Lucie Navratilova

The facile synthesis, solution-processability, and outstanding optoelectronic properties of emerging colloidal lead halide perovskite quantum dots (LHP QDs) makes them ideal candidates for scalable and inexpensive optoelectronic applications, including pho ...

Wiley-VCH Verlag GmbH2019

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

Effects of co-doped barium cerate additive on morphology, conductivity and electrochemical properties of samarium doped ceria electrolyte for intermediate temperature solid oxide fuel cells

Yongpeng Liu, Xinchao Wang, Chiara Bonati, Meng Xia

The composite of samarium doped ceria (Sm0.2Ce0.8O2-delta, SDC) and co-doped barium cerate (BaZr0.1Ce0.7Y0.1Yb0.1O3-delta, BZCYYb) is prepared by mechanical mixing and investigated as electrolyte for intermediate temperature solid oxide fuel cells (IT-SOFC ...

PERGAMON-ELSEVIER SCIENCE LTD2018

Spectroelectrochemical and Chemical Evidence of Surface Passivation at Zinc Ferrite (ZnFe 2 O 4 ) Photoanodes for Solar Water Oxidation

Michael Graetzel, Kevin Sivula, Liang Yao, Mounir Driss Mensi, Nestor Guijarro Carratala, Dan Ren, Yongpeng Liu, Meng Xia

Recent advances in low‐cost manufacturing as well as in bulk/interface engineering have positioned zinc ferrite (ZnFe2O4, ZFO) in the spotlight as a candidate material for solar water oxidation. However, the severe recombination at the reactive interface r ...

2021