Publications by Nestor Guijarro Carratala

Ink-Based CuIn0.3Ga0.7S2 Nanocrystal Thin Films as Photocathodes for Photoelectrochemical CO2 Reduction Reaction

Jun Ho Yum, Kevin Sivula, Nestor Guijarro Carratala

One of the promising methods to solve the current energyand environmentissues is photoelectrochemical (PEC) water splitting and CO2 reduction reaction. Chalcopyrite copper indium gallium sulfide (CIGS)and CuIn0.3Ga0.7S2 nanocrystal thinfilms have been cons ...

AMER CHEMICAL SOC2023

Photoelectrochemical CO2 Reduction at a Direct CuInGaS2/Electrolyte Junction

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

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

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

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

Benzodithiophene‐Based Spacers for Layered and Quasi‐Layered Lead Halide Perovskite Solar Cells

Mounir Driss Mensi, Jun Ho Yum, Kevin Sivula, Nestor Guijarro Carratala, Luc Emile Monnier, Liang Yao, Barbara Alexandra Primera Darwich, Han-Hee Cho

Incorporating extended pi-conjugated organic cations in layered lead halide perovskites is a recent trend promising to merge the fields of organic semiconductors and lead halide perovskites. Herein, we integrate benzodithiophene (BDT) into Ruddlesden–Poppe ...

2021

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

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

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

A semiconducting polymer bulk heterojunction photoanode for solar water oxidation

Jun Ho Yum, Kevin Sivula, Nestor Guijarro Carratala, Arvindh Sekar, Liang Yao, Yongpeng Liu, Rebekah Anne Wells, Florent Alexandre Boudoire, Han-Hee Cho

Organic semiconductors hold promise to enable scalable, low-cost and high-performance artificial photosynthesis. However, the performance of systems based on organic semiconductors for light-driven water oxidation have remained poor compared with inorganic ...

NATURE RESEARCH2021

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

Kevin Sivula, Florian Le Formal, Nestor Guijarro Carratala, 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

Identifying Reactive Sites and Surface Traps in Chalcopyrite Photocathodes

Michael Graetzel, Mounir Driss Mensi, Kevin Sivula, Nestor Guijarro Carratala, Liang Yao, 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

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

Kevin Sivula, Nestor Guijarro Carratala, Liang Yao, 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

Defect engineered nanostructured LaFeO3 photoanodes for improved activity in solar water oxidation

Mounir Driss Mensi, Kevin Sivula, Xavier Pereira Da Costa, Nestor Guijarro Carratala, Liang Yao, Yongpeng Liu

LaFeO3 (LFO) is recognized as a candidate material for solar water oxidation, but its photoelectrochemical response remains modest and stagnant. With the aim of advancing LFO photoanodes for the oxygen evolution reaction (OER), here, a nanorod array-type e ...

Royal Society of Chemistry2021

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

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

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

Establishing Stability in Organic Semiconductor Photocathodes for Solar Hydrogen Production

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

Taking lanthanides out of isolation: tuning the optical properties of metal-organic frameworks

Kevin Sivula, Gloria Capano, Muhammad Aiman Bin Rahmanudin Hamdan, Nestor Guijarro Carratala, Berend Smit, Samantha Lynn Anderson, Kyriakos Stylianou, Davide Tiana, Andrzej Gladysiak, Christopher Patrick Ireland, Stavroula Kampouri, Maria Fumanal Quintana

Metal organic frameworks (MOFs) are increasingly used in applications that rely on the optical and electronic properties of these materials. These applications require a fundamental understanding on how the structure of these materials, and in particular t ...

2020

Generalized Synthesis to Produce Transparent Thin Films of Ternary Metal Oxide Photoelectrodes

Kevin Sivula, Nestor Guijarro Carratala, Liang Yao, Florent Alexandre Boudoire, Charles Roger Jean Lhermitte, Annalisa Polo

Developing facile approaches to prepare non-light-scattering ternary oxide thin film photoelectrodes is an important goal for solar water splitting tandem cells. Herein, a novel synthesis route is reported that employs ethylenediaminetetraacetic acid (EDTA ...

WILEY-V C H VERLAG GMBH2020

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

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, Feiping Zhao

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

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

Kevin Sivula, Nestor Guijarro Carratala, Andreas Züttel, 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

In Situ Electrochemical Oxidation of Cu2S into CuO Nanowires as a Durable and Efficient Electrocatalyst for Oxygen Evolution Reaction

Kevin Sivula, Nestor Guijarro Carratala, Yongpeng Liu, Yong Zuo, Ting Zhang

Development of cost-effective oxygen evolution catalysts is of capital importance for the deployment of large-scale energy-storage systems based on metal-air batteries and reversible fuel cells. In this direction, a wide range of materials have been explor ...

AMER CHEMICAL SOC2019

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

Kevin Sivula, Florian Le Formal, Nestor Guijarro Carratala, Liang Yao, 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