MEchanics GAthering –MEGA- Seminar: Photoelectrochemical water splitting under high irradiances (> 100 suns)
Event details
| Date | 16.11.2023 |
| Hour | 16:15 › 17:30 |
| Speaker | Franky Bedoya-Lora (LRESE, EPFL) |
| Location | Online |
| Category | Conferences - Seminars |
| Event Language | English |
Abstract:
The production of solar fuels by using concentrated irradiation allows for smaller and cheaper devices, and ultimately lower fuel production costs, with the added benefit of increased performances if operating conditions are chosen judiciously [1]. Photoelectrochemical (PEC) water splitting, for example to produce hydrogen as a solar fuel, has been studied mostly at room temperature and under 1 sun illumination, hence there are still unrealized possibilities for hydrogen production by using high irradiances, for example higher than 100 suns, where 1 sun is approx. 1 kW m-2. However, the potentially advantageous synergy between higher temperatures and irradiation, also renders the system complex and difficult to study. The effect of temperature alone on photoelectrode performances has been reported for several semiconducting materials, e.g. Fe2O3 [2] and BiVO4 [3]; while the effect of high photon fluxes has been investigated separately up to 30 suns [4]. The combined effects of temperature and high irradiations on the performance of PEC devices has been rarely investigated experimentally, this is mostly due to the complexity of decoupling the effects due to increased surface temperature, photon fluxes and degradation rates.
Under high irradiances, two main coupled effects are to be investigated: (i) the effect of temperature on the reaction kinetics and properties of the semiconductor, and (ii) the effect of high photon fluxes on the transport of charge carriers and its distribution towards fuel production, recombination or photodegradation.
With the aim to address this challenge, we developed a new PEC cell for operation at high irradiations, 30 – 360 suns, along with a multiphysics model to predict the increased surface temperature and the inevitable effects related to ohmic drop, bubble evolution and current density distribution. In this talk, the effect of high irradiances on the performances of two semiconductors (BiVO4 and Fe2O3) will be presented and how their performance affects the engineering and design of photoelectrochemical cells to be used under high irradiances.
[1] Tembhurne, S. et al. J. Electrochem. Soc. 163, H999 (2016)
[2] Ye, X. et al. J. Mater. Chem. A 3, 10801–10810 (2015)
[3] Jiang, W. et al. Appl. Catal. B 304, 121012 (2022)
[4] Segev, G. et al. Adv. Energy Mater. 6, 1500817, (2016)
Biography:
Franky Bedoya-Lora is a postdoctoral researcher working at the Laboratory of Renewable Energy Science and Engineering (LRESE). Currently, his research is focused on the degradation of photoelectrode materials and solar fuel production under high irradiances. He obtained his PhD on electrochemical engineering and photoelectrochemistry at Imperial College London (United Kingdom), and has a master from Universidad de Antioquia (Colombia) on electrochemical methods for the assessment of anticorrosive coatings. His main topics of research are electrochemical energy storage and conversion, electrochemical engineering and corrosion.
The production of solar fuels by using concentrated irradiation allows for smaller and cheaper devices, and ultimately lower fuel production costs, with the added benefit of increased performances if operating conditions are chosen judiciously [1]. Photoelectrochemical (PEC) water splitting, for example to produce hydrogen as a solar fuel, has been studied mostly at room temperature and under 1 sun illumination, hence there are still unrealized possibilities for hydrogen production by using high irradiances, for example higher than 100 suns, where 1 sun is approx. 1 kW m-2. However, the potentially advantageous synergy between higher temperatures and irradiation, also renders the system complex and difficult to study. The effect of temperature alone on photoelectrode performances has been reported for several semiconducting materials, e.g. Fe2O3 [2] and BiVO4 [3]; while the effect of high photon fluxes has been investigated separately up to 30 suns [4]. The combined effects of temperature and high irradiations on the performance of PEC devices has been rarely investigated experimentally, this is mostly due to the complexity of decoupling the effects due to increased surface temperature, photon fluxes and degradation rates.
Under high irradiances, two main coupled effects are to be investigated: (i) the effect of temperature on the reaction kinetics and properties of the semiconductor, and (ii) the effect of high photon fluxes on the transport of charge carriers and its distribution towards fuel production, recombination or photodegradation.
With the aim to address this challenge, we developed a new PEC cell for operation at high irradiations, 30 – 360 suns, along with a multiphysics model to predict the increased surface temperature and the inevitable effects related to ohmic drop, bubble evolution and current density distribution. In this talk, the effect of high irradiances on the performances of two semiconductors (BiVO4 and Fe2O3) will be presented and how their performance affects the engineering and design of photoelectrochemical cells to be used under high irradiances.
[1] Tembhurne, S. et al. J. Electrochem. Soc. 163, H999 (2016)
[2] Ye, X. et al. J. Mater. Chem. A 3, 10801–10810 (2015)
[3] Jiang, W. et al. Appl. Catal. B 304, 121012 (2022)
[4] Segev, G. et al. Adv. Energy Mater. 6, 1500817, (2016)
Biography:
Franky Bedoya-Lora is a postdoctoral researcher working at the Laboratory of Renewable Energy Science and Engineering (LRESE). Currently, his research is focused on the degradation of photoelectrode materials and solar fuel production under high irradiances. He obtained his PhD on electrochemical engineering and photoelectrochemistry at Imperial College London (United Kingdom), and has a master from Universidad de Antioquia (Colombia) on electrochemical methods for the assessment of anticorrosive coatings. His main topics of research are electrochemical energy storage and conversion, electrochemical engineering and corrosion.
Practical information
- General public
- Free
Organizer
- MEGA.Seminar Organizing Committee