An international team has now succeeded in considerably increasing the efficiency for direct solar water splitting. They are using a tandem solar cell whose surfaces have been selectively modified. The new record value is 14 % and thus considerably above the previous record of 12.4 % held by the National Renewable Energy Laboratory (NREL) in the USA, broken now for the first time in 17 years.
Researchers from the Institute for Solar Fuels at the Helmholtz-Zentrum Berlin, TU Ilmenau, the Fraunhofer Institute for Solar Energy Systems ISE in Freiburg and the California Institute of Technology (Caltech) participated in the collaboration. The results have been published in Nature Communications.
Solar energy is abundantly available globally, but unfortunately not constantly and not everywhere. One especially interesting solution for storing this energy is artificial photosynthesis. This is what every leaf can do, namely converting sunlight to “chemical energy”. That can take place with artificial systems based on semiconductors as well. These use the electrical power that sunlight creates in individual semiconductor components to split water into oxygen and hydrogen. Hydrogen possesses very high energy density, can be employed in many ways and could replace fossil fuels. In addition, no carbon dioxide harmful to the climate is released from hydrogen during combustion, instead only water. Until now, manufacturing of solar hydrogen at the industrial level has failed due to the costs, however. This is because the efficiency of artificial photosynthesis, i.e. the energy content of the hydrogen compared to that of sunlight, has simply been too low to produce hydrogen from the sun economically.
Record value now exceeded
Scientific facilities worldwide have therefore been researching for many years how to break the existing record for artificial photosynthesis of 12.4 %, which has been held for 17 years by NREL in the USA.
Core component: Tandem Solar Cell
Now a team from TU Ilmenau, HZB, the California Institute of Technology as well as the Fraunhofer ISE has
considerably exceeded this record value. Lead author Matthias May, active at TU Ilmenau and the HZB Institute for Solar Fuels, processed and surveyed about one hundred samples in his excellent doctoral dissertation to achieve this. The fundamental components are tandem solar cells of what are known as III-V semiconductors. Using a now patented photo-electrochemical process, May could modify certain surfaces of these semiconductor systems in such a way that they functioned better in water splitting.
“We have electronically and chemically passivated in situ the aluminium-indium-phosphide layers in particular and thereby efficiently coupled to the catalyst layer for hydrogen generation. In this way, we were able to control the composition of the surface at sub-nanometre scales”, explains May. There was enormous improvement in long-term stability as well. At the beginning, the samples only survived a few seconds before their power output collapsed. Following about a year of optimising, they remain stable for over 40 hours. Further steps toward a long-term stability goal of 1000 hours are already underway.
Next goals visible
“Forecasts indicate that the generation of hydrogen from sunlight using high-efficiency semiconductors could be economically competitive to fossil energy sources at efficiency levels of 15 % or more.
The Latest on: Artificial photosynthesis
via Google News
The Latest on: Artificial photosynthesis
- Artificial Photosynthesis Helps Address Environmental Pollution and Global Warmingon January 21, 2020 at 8:25 am
This process does not leave behind any byproducts in water. The study has been published in the Materials Today journal. It is essential to identify an optimal high-performance photocatalyst to ...
- New Artificial Photosynthesis – The Methane-Generating Methodon January 16, 2020 at 1:24 am
Photosynthesis is the process by which plants, and even several bacterias, use the energy from sunlight to generate glucose from carbon dioxide and water, giving oxygen in return as a byproduct.
- Fake photosynthesis turns CO2 into ‘green methane’on January 13, 2020 at 1:10 pm
A new artificial photosynthesis approach uses sunlight to turn carbon dioxide into methane, which could help make natural-gas-powered devices carbon neutral. Methane is the main component of natural ...
- 'Green methane' from artificial photosynthesis could recycle CO2on January 13, 2020 at 4:52 am
A new artificial photosynthesis approach uses sunlight to turn carbon dioxide into methane, which could help make natural-gas-powered devices carbon neutral. The methane-generating method is made ...
- How a scientific breakthrough is making "green methane"on January 11, 2020 at 2:52 pm
Scientists are creating “green methane” out of a process called artificial photosynthesis — which could make natural-gas-powered devices carbon neutral.
- Okayama University e-Bulletin: Excellence in Research on Artificial Photosynthesison December 24, 2019 at 3:27 am
Okayama University e-Bulletin highlights news and views from one of Japan's largest comprehensive universities internationally recognized for its dynamic and innovative approach to ...
- Okayama University e-Bulletin: Excellence in Research on Artificial Photosynthesison December 24, 2019 at 3:22 am
OKAYAMA, Japan, Dec. 24, 2019 /PRNewswire/ -- This issue includes a feature on "Jian-Rena Shen research on artificial photosynthesis." Other contents include news on "Okayama University ...
- Advancing photosystem II photoelectrochemistry for semi-artificial photosynthesison December 21, 2019 at 9:19 am
Furthermore, these studies have accelerated the development of semi-artificial photosynthesis to afford autonomous, solar-driven, fuel-forming biohybrid devices. This Review summarizes the latest ...
- DoE achieves breakthrough in artificial photosynthesison December 6, 2019 at 2:35 am
Researchers at the Department of Energy (DoE) have achieved a chemical reaction that drastically improves upon current methods for artificial photosynthesis, providing a new process for the ...
- Japan research on photosynthetic process paves way for artificial conversionson October 26, 2019 at 5:31 pm
The team says that its work has provided important data for work toward making artificial photosynthesis a reality. Photosynthesis, which uses sunlight to convert water and carbon dioxide into ...
via Bing News