Contact

How to Produce Hydrogen Through Photosynthesis

By

November 29, 2016

Image titel:

Sources:

How to Produce Hydrogen Through Photosynthesis

FZ-Juelich

Hydrogen formation, © FZ Jülich

Hydrogen is thought to be a highly efficient and an almost perfect solution for energy storage. And its importance is growing in light of the volatility of renewable energies. But the conventional and rather complicated hydrogen generation through solar energy and subsequent electrolysis reduces the efficiency of the process. An interesting alternative could be artificial photosynthesis, for which researchers all over the world are developing the methods. Success and efficiency both hinge on suitable materials for the cells. The technological battle for the best efficiency (which has doubled over the last years) is in full force.

Plants have long been able to convert sunlight into chemical energy through photosynthesis. Solar energy captured by technological means may indeed be available worldwide in abundance, but not all the time and everywhere. The development of solutions storing solar power in batteries or hydrogen has a long way to go, and this although any harnessed energy could be captured much better in the form of hydrogen than electrically. Professor Roel van de Krol, who heads the Solar Fuels Institute at the Helmholtz Zentrum Berlin (HZB), explained: “One kilogram of a fuel like hydrogen stores about 100 times as much energy as a comparable battery.” A particularly interesting storage solution is one based on nature itself: artificial photosynthesis, a technology that is being researched across the globe.

Artificial leaf produces hydrogen

It has already been possible today to convert sunlight into chemical energy through artificial semiconductor systems. The “artificial leaf” required for the process consists of a solar cell, two electrodes and a membrane, combined with added functional layers. If immersed in water and put in sunlight, the harnessed electrical energy at the photoanode splits the water into oxygen atoms, protons and electrons, i.e., hydrogen. Whereas the oxygen remains in one chamber, the electrons and protons are led through the membrane into another, where a photoanode is used to combine them into hydrogen.

At present, there are still some issues to work out: Despite the additional layers of material, enough light must come through the solar cell to create the voltage for splitting water. Moreover, the semiconductor materials …

link-to-e-journal-web

Above 15% efficiency

An international team made up of researchers from the Helmholtz Zentrum Berlin, the TU Ilmenau, the Fraunhofer Institute for Solar Energy Systems and the Joint Center for Artificial Photosynthesis (JCAP) of the California Institute of Technology has now succeeded in increasing the efficiency for direct solar water splitting a second time. The new benchmark value is 14 percent. The researchers used …

“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. This corresponds to a hydrogen price of about four US dollars per kilogram,” Professor Thomas Hannappel from the TU Ilmenau said. Professor Hans-Joachim Lewerenz from JCAP, who worked closely with the researchers from the HZB, added: “We’re nearly there. If we also manage to increase charge carrier mobility at the junctions a bit further, we could even use this semiconductor system to store more than 17 percent of the incident sunlight chemically as hydrogen.”

Search for inexpensive catalysts

In research, higher efficiency goes hand in hand with a search for inexpensive and efficient catalysts which are required at the anode for water splitting and the decrease of reaction times. So far, the process has used effective but expensive metals like platinum. Conversely, the artificial leaf contains a JCAP-developed catalyst that is cheap and consists of a two-nanometer-thick nickel layer to increase efficiency. Another 62.5 nm thin film of TiO2 prevents corrosion and improves the stability of the gallium-arsenic photoelectrode. A principal element of the JCAP development is the plastic membrane that keeps the oxygen and the hydrogen gases separate to prevent the creation of oxyhydrogen.

More layers = more capacity

There are yet other organizations which explore the potential of solar-based hydrogen production: Researchers from the Institute of Energy and Climate Research at the Jülich Research Center have developed a silicon-made multi-layer solar cell that can be produced quite cost-effectively and creates hydrogen based on artificial photosynthesis directly from sunlight. The efficiency achieved so far is 9.5 percent. “The difficulty, however, is to create a sufficiently high photovoltage. In practice, around 1.6 volts are necessary to kick-start the reaction for water splitting. Common crystal silicon solar cells, which have a photovoltage considerably lower than one volt cannot accomplish that,” explained Jan-Philipp Becker.

Algae and cyanobacteria

Researchers from the Center for Biotechnology at Bielefeld University are working on a way to utilize proteins from algae and semiconductor nanomaterials to capture the energy of the sun. This energy will then be used by the new artificially created catalysts to produce hydrogen. And researchers at the Hebrew University in Jerusalem have already coupled the light-absorbing parts of cyanobacteria with an electrode for biocatalytic power generation. By using a polymer and a nanoparticle made of platinum, they managed to link the light-harvesting complexes and reaction centers of cyanobacteria photosystems to an electrode through oxygen molecules. If sunlight enters a cell, the glucose molecules can convert it into gluconic acid with the help of special enzymes. The released electrons move to the electrode and can be fed into an electric circuit. At present, however, these bacteria only achieve a modest 1% efficiency.

Author: Edgar Lange, freelance journalist specializing in fuel cells and hydrogen

Here are interesting and current articles on the topic of hydrogen – stocks and the stock market!

Economic prospects for companies in the hydrogen sector | Future, stocks & hydrogen companies on the stock exchange and more…

Which hydrogen companies will prevail in the competitive market in the long term? Get tips and cartwheels and learn more about risks or opportunities. Our stock market specialist and expert author Sven Jösting reports critically, independently and competently.

Feb 19 2025

Biggest change in the history of the cement industry

Interview with Erkam Kocakerim, CEO of Limak Cement Global Together with Air Liquide, Limak Cement...
Feb 17 2025

From CO2 capture to LOHC technology

Interview with Bryan Glover, CTO of Honeywell After more than 50 years of experience with...
Feb 17 2025

Reliable operation of fuel cells

System solutions for hydrogen supply and water separation Fuel cell systems have much fewer...
Feb 17 2025

The cleaner, the more support

Interview with Michelle Lujan Grisham, Governor of the US state of New Mexico The US is investing...
Feb 17 2025

Hydrogen for racing cars

Formula Student relies on H2 In the summer of 2025, the first hydrogen vehicles will compete...
Feb 13 2025

Shortage of skilled workers in the hydrogen economy

Various training courses at different institutions For around five years, the number of employees...
Feb 13 2025

Changes on the horizon

What developments! We are living in turbulent times. Several transformative processes are...
Feb 13 2025

Maximizing MEA efficiency with minimal iridium

The problem with iridium dependency The push for more sustainable hydrogen generation has never...
Feb 05 2025

The hydrogen economy needs to develop at greater speed

UFI Hydrogen may not yet be particularly well known to many industry participants in Germany, but...
Feb 05 2025

Hydrogen terminal in Braunschweig

Green hydrogen for research A research environment along the H2 value chain is being created at...
Jan 31 2025

Hydrogen production directly on the high seas

H2Mare researches offshore technologies Offshore wind power stations generate significantly more...
Jan 30 2025

Material testing as a guarantee of safety

Upgrading the gas infrastructure For hydrogen to be able to be used as an important part of the...
Jan 20 2025

The SHIMMER project

European multi-gas network is launched In the EU project SHIMMER, the German institute for...
Jan 17 2025

HH2E files for insolvency

Big plans and professional marketing – HH2E’s appearance was downright impressive, but on...
Jan 17 2025

No doubts about the core network

Gas network operators continue to count on political support In October 2024, the German Federal...
Jan 17 2025

Proton Motor lays off employees

The German fuel cell manufacturer Proton Motor has announced the provisional end of its production...
Jan 15 2025

ZBT expands HyTechLab4NRW

Nordrhein-Westfalen is further expanding its capacities in the H2 research sector. In September...
Jan 15 2025

Enertrag opens office in Hamburg

To strengthen its “role in the global hydrogen economy,” Enertrag, a developer and producer of...
Jan 13 2025

Construction and conversion of the infrastructure for H2 distribution

"Hydrogen can come, the gas distribution network is ready" There is extensive demand for hydrogen...
Jan 13 2025

Only a few stocks are on the winning side

Share analysis by Jörg Weber, ECOreporter The great excitement surrounding hydrogen seems to be...

0 Comments

Leave a Reply

Discover more from H2-international

Subscribe now to keep reading and get access to the full archive.

Continue reading