Proceedings of MATSUS Fall 2023 Conference (MATSUSFall23)
Publication date: 18th July 2023
Photoelectrochemical (PEC) water splitting is one of the few truly renewable pathways towards “green” H2. Operating PEC water splitting at elevated pressure offers many benefits. For example, bubble formation is strongly reduced at elevated pressure, which lowers bubble-induced electrode deactivation and bubble-induced product crossover rate.[1,2] In addition, the optical reflection and diffraction losses induced by bubbles can be minimized.[3] Finally, the electrochemical production of hydrogen at higher pressure requires only a small (though not insignificant) increase of the thermodynamic cell voltage (29 mV for 10-fold increase in pressure).[4] However, bubble dynamics in a photoelectrochemical cell at elevated pressure, e.g. bubble diameter and bubble coverage on the photoelectrode, remain unclear, therefore need to be investigated. In this work, we conducted a shadowgraphy study on galvanostatically formed O2 bubbles in a pressurized (1-4 bar) PEC water splitting cell, as shown schematically in Fig. 1a. BiVO4 was electrochemically prepared on an FTO substrate and used as the anode, with Pt wire and a leak-less Ag/AgCl as the cathode and reference electrode, respectively. The electrolyte was 0.1 M potassium borate buffer (KBi, pH9). As shown in Fig. 1b, an instant drop in cell potential was observed while elevating the cell pressure from 1 bar to 2 bar. Using bubble shadowgraphy (Fig. 1c), we could correlate this cell potential drop with the shrinkage of bubble diameter. Interestingly, further pressurizations, i.e. from 2 bar to 3 bar and from 3 bar to 4 bar, led to only minor changes in both the cell potential and bubble diameter. The quantitative impact of this observation with respect to the various loss mechanism in a PEC cell (e.g. thermodynamic, optical loss, product crossover, activation) will be discussed. Overall, the findings from this work serve as a guideline in designing highly efficient photoelectrochemical water splitting cell at elevated pressure.
The Helmholtz Association of German Research Centers (HGF) and the Federal Ministry of Education and Research (BMBF), Germany are gratefully acknowledged for supporting the development of solar powered technologies for H2 generation within the frame of the Innovation Pool project “Solar H2: Highly Pure and Compressed” and the Helmholtz Research Program “Materials and Technologies for the Energy Transition” (MTET). Part of the work was also carried out with the support of the Helmholtz Energy Materials Foundry (HEMF), a large-scale distributed research infrastructure founded by the German Helmholtz Association.
nanoGe is a prestigious brand of successful science conferences that are developed along the year in different areas of the world since 2009. Our worldwide conferences cover cutting-edge materials topics like perovskite solar cells, photovoltaics, optoelectronics, solar fuel conversion, surface science, catalysis and two-dimensional materials, among many others.
Previously nanoGe Spring Meeting (NSM) and nanoGe Fall Meeting (NFM), MATSUS is a multiple symposia conference focused on a broad set of topics of advanced materials preparation, their fundamental properties, and their applications, in fields such as renewable energy, photovoltaics, lighting, semiconductor quantum dots, 2-D materials synthesis, charge carriers dynamics, microscopy and spectroscopy semiconductors fundamentals, etc.
International Conference on Hybrid and Organic Photovoltaics
International Conference on Hybrid and Organic Photovoltaics (HOPV) is celebrated yearly in May. The main topics are the development, function and modeling of materials and devices for hybrid and organic solar cells. The field is now dominated by perovskite solar cells but also other hybrid technologies, as organic solar cells, quantum dot solar cells, and dye-sensitized solar cells and their integration into devices for photoelectrochemical solar fuel production.
Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics
The main topics of the Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics (IPEROP) are discussed every year in Asia-Pacific for gathering the recent advances in the fields of material preparation, modeling and fabrication of perovskite and hybrid and organic materials. Photovoltaic devices are analyzed from fundamental physics and materials properties to a broad set of applications. The conference also covers the developments of perovskite optoelectronics, including light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.
The International Conference on Perovskite Thin Film Photovoltaics Perovskite Photonics and Optoelectronics (NIPHO) is the best place to hear the latest developments in perovskite solar cells as well as on recent advances in the fields of perovskite light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.