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The Electrochemical Society is a learned society (professional association) based in the United States that supports scientific inquiry in the field of electrochemistry and solid-state science and related technology. The Society membership comprises more than 8,000 scientists and engineers in over 85 countries at all degree levels and in all fields of electrochemistry, solid state science and related technologies. Additional support is provided by institutional members including corporations and laboratories. ECS is a 501(c)(3) non-profit organization. Scientists around the world rely on the Society as a leading source of scientific research through its peer-reviewed journals, international meetings, and the ECS Digital Library on IOPscience. The Society publishes numerous journals including the Journal of The Electrochemical Society (the oldest peer-reviewed journal in its field), Journal of Solid State Science and Technology, ECS Meeting Abstracts, ECS Transactions, and ECS Inter

Photoelectrochemical Oxygen Evolution on Mesoporous Hematite Films Prepared from Maghemite Nanoparticles

Michael Graetzel, Nathália Carolina Verissimo, Shaik Mohammed Zakeeruddin

Iron oxides, especially hematite (alpha-Fe2O3), a are promising materials for applications in photoelectrochemical cells and photo-redox catalysis. However, realizing high-performance hematite photoanodes via an environmentally-friendly route remains a great challenge. In this work, we employed a novel approach to prepare mesoscopic hematite photoelectrodes with remarkable performance for water oxidation. Hydrothermally-synthesized maghemite nanoparticles of high crystallinity with a mean particle size of 3.3 nm were deposited onto fluorine doped tin oxide (FTO) transparent conducting glass substrates, followed by heat treatment to convert them into a homogeneous mesoporous hematite layer. A hematite photoanode with a thickness of 220 nm, delivered a maximum photocurrent density of 1.8 mA cm(-2) for water oxidation to oxygen at 1.23 V-RHE under simulated AM 1.5 irradiation. Upon treating the surface of the hematite photoelectrode with Co(II) cations the photocurrent density nearly doubled at the same potential to 3.32 mA cm(-2) placing our new photoelectrode among the best hematite-based photocatalysts for visible light induced water splitting. Further photoelectrochemical analysis provided insights into the factors boosting the performance of the hematite photoanode. (C) 2022 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited.

ELECTROCHEMICAL SOC INC2022

A DEMS study of methanol and formic acid oxidation on boron-doped diamond electrode

Christos Comninellis, György Foti, Agnieszka Kapalka

The electrochemical oxidation of methanol and formic acid in 1 M HClO4 is studied on boron-doped diamond electrode using differential electrochemical mass spectrometry (DEMS). DEMS is used to identify products and intermediates of the reaction monitored online during the potential sweep. The measurements show that the oxidation of both methanol and formic acid proceeds close to the potential of the oxygen evolution reaction, resulting in the appearance of an oxidation wave. During the oxidation, the oxygen evolution reaction shifts toward a higher potential, i.e., becomes a secondary reaction. Depending on the potential, either the formation of intermediates (partial oxidation) or the complete mineralization of organics, simultaneous with oxygen evolution, is observed. Diffusion limitation of the oxidation is clearly observed in parallel to the increase in O-2 formation. Methylformate is formed from methanol at potentials at which the local concentration of OH radicals is not sufficient for a complete mineralization. Formic acid oxidation proceeds in two waves; before the onset of oxygen evolution, an intermediate (probably oxalic acid) is produced in parallel to CO2 formation. Only in parallel to oxygen evolution is mineralization to CO2 is complete. (C) 2009 The Electrochemical Society. [DOI: 10.1149/1.3207009] All rights reserved.

2009

Solar-to-Hydrogen Production at 14.2% Efficiency with Silicon Photovoltaics and Earth-Abundant Electrocatalysts

Julien Claude Bailat, Christophe Ballif, Enrico Chinello, Antonio Delfino, Matthieu Despeisse, Antonin Faes, David Lambelet, Miguel Antonio Modestino, Christophe Moser, Demetri Psaltis, Jan-Willem Alexander Schüttauf

Affordable, stable and earth-abundant photo-electrochemical materials are indispensable for the large-scale implementation of sunlight-driven hydrogen production. Here we present an intrinsically stable and scalable solar water splitting device that is fully based on earth-abundant materials, with a solar-to-hydrogen conversion efficiency of 14.2%. This unprecedented efficiency is achieved by integrating a module of three interconnected silicon heterojunction solar cells that operates at an appropriate voltage to directly power microstructured Ni electrocatalysts. Nearly identical performance levels were also achieved using a customized state-of-the-art proton exchange membrane (PEM) electrolyzer. As silicon heterojunction solar cells and PEM electrolysis systems are commercially viable, easily scalable and have long lifetimes, the devices demonstrated in this report can open a fast avenue toward the industrialization and deployment of cost effective solar-fuel production systems. (C) 2016 The Electrochemical Society. All rights reserved.

Electrochemical Society2016