Artificial photosynthesis has carved out a promising corner in renewable energy research in recent history. This novel process is solar-driven, harvesting renewable energy and storing in in chemical bonds. Breakthroughs in artificial photosynthesis could lead to the development of solar fuels that could potentially shift the energy infrastructure.

However, while many technological barriers have been surpassed in the advancement of artificial photosynthesis, there are still hurdles to overcome. However, a research team from Forschungszentrum Juelich believes they may have just taken a significant step forward in the advancement of this field.

In a recently published paper, the team of scientists state that they have developed the first complete and compact design for an artificial photosynthesis facility.

The artificial photosynthesis process was first investigated in the 1970s. In fact, ECS Fellow Allen J. Bard can be seen here discussing the process in 1983. But only recently has artificial photosynthesis began to garner larger amounts of attention from the scientific community as a whole.


An interdisciplinary team of researchers based out of the University of Illinois at Chicago believes they may have just changed the game in solar cell technology.

According to the recently published study, the team promises a solar cell that not only harvests energy, but cheaply and efficiently transforms atmospheric carbon dioxide into useable hydrocarbon fuel – all with a little help from the sun.

The new development differs from typical solar technology, where the cells convert sunlight into energy to be stored in batteries or other energy storage devices. Instead, the new research uses solar cells in a way similar to organic photosynthesis, just amplified.

By capturing dangerous greenhouse gases and converting them into alternative, clean fuels, the researchers believe a farm full of these “artificial leaf” solar cells could begin to significantly reduce the amount of carbon dioxide in the environment and help shift the energy landscape toward more green alternatives.

“The new solar cell is not photovoltaic—it’s photosynthetic,” says Amin Salehi-Khojin, senior author of the study. “Instead of producing energy in an unsustainable one-way route from fossil fuels to greenhouse gas, we can now reverse the process and recycle atmospheric carbon into fuel using sunlight.”


Clean Energy from Water

For most of history, fuel cells existed only as laboratory curiosities. As far back as 1839, the English scientist William Grove had the idea that the reactants of a battery could be gases fed into it from external tanks.

Since their humble beginnings, fuel cells have come a far to prove as a viable alternative to combustion. Currently, researchers at the University of Basel are studying how sunlight could split water into hydrogen and oxygen, creating a fuel cell that could produce clean energy from water.

(MORE: Read “Battery and Fuel Cell Technology.”)

Artificial photosynthesis has proven to be one of the most promising tools in producing clean, renewable resources. This process occurs when water is photo-electrochemically, with the aid of sunlight, separated into its H2 and O2 components.

Of the two reactions that occur, water oxidation typically provides researchers with the most hurdles to overcome. The new research works to develop an efficient, sustainable water oxidation catalyst.


Teaching Bacterium a New Trick

Scientists are teaching old bacterium some new tricks in an effort to advance artificial photosynthesis.

The bacterium Moorella thermoacetica has been trained to perform photosynthesis, even though it is non-photosynthetic. All of this comes with a push to convert sunlight into valuable chemical products for a cleaner, greener energy future.

“We’ve demonstrated the first self-photosensitization of a non-photosynthetic bacterium, M. thermoacetica, with cadmium sulfide nanoparticles to produce acetic acid from carbon dioxide at efficiencies and yield that are comparable to or may even exceed the capabilities of natural photosynthesis,” says Peidong Yang, lead researcher of this work.

Previously, Yang’s work has centered around the development of the artificial “leaf,” which aims to produce natural gas from carbon dioxide. This extension of that work is still in line with the development of a clean energy future.

(MORE: Read more of Yang’s research in the ECS Digital Library.)

“In our latest study, we combined the highly efficient light harvesting of an inorganic semiconductor with the high specificity, low cost, and self-replication and self-repair of a biocatalyst,” Yang says. “By inducing the self-photosensitization of M. thermoacetica with cadmium sulfide nanoparticles, we enabled the photosynthesis of acetic acid from carbon dioxide over several days of light-dark cycles at relatively high quantum yields, demonstrating a self-replicating route toward solar-to-chemical carbon dioxide reduction.”

Record-Breaking Energy Efficiency Levels

An interdisciplinary team has set a new record for direct solar water splitting efficiency. Surpassing the 17 year old record of 12.4 percent, the new achieved efficiency level of 14 percent guarantees a promising future for solar hydrogen production.

While the potential for renewable energy is available across the globe, the ability to harvest and store this energy is not. One solution to achieving global renewable energy is through artificial photosynthesis.

How to Power the Future

Much like organic photosynthesis, artificial photosynthesis coverts sunlight into chemical energy. This highly-researched concept also has the ability to be carried into semiconductor technology.

Essentially, researchers can take the sun’s electrical power and split water into oxygen and hydrogen with high energy density levels. This type of development has the potential to replace current fossil fuels and create a type of energy that does not emit harmful carbon dioxide.

The concept has not been utilized on a commercial level due to the high cost. However, this new development could raise the efficiency levels to a high enough percentage to make the process economically viable.

This from the Helmholtz Association of German Research Centres:

Lead author Matthias May … 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.


Could These ‘Plants’ Fuel the Future?

Scientists working in the field of synthetic photosynthesis have recently developed an artificial “leaf” the can produce natural gas from carbon dioxide. This marks a major step toward producing renewable fuels.

Through a combination of semiconducting nanowires and bacteria, the researchers were able to design an artificial plant that can make natural gases using only sunlight—making the likelihood of a cleaner future more tangible.

From Organic to Synthetic

The roots of this development stem for the natural process of photosynthesis. Instead of the natural byproduct of organic photosynthesis (sugar), these scientists have produced methane.

“We’re good at generating electrons from light efficiently, but chemical synthesis always limited our systems in the past,” said Peidong Yang, head researcher in the study. “One purpose of this experiment was to show we could integrate bacterial catalysts with semiconductor technology. This lets us understand and optimize a truly synthetic photosynthesis system.”


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Image: Joint Center for Artificial Photosynthesis (JCAP) [Click to enlarge]

The fifth international ECS Electrochemical Energy Summit (E2S) will take place October 12-14, 2015 during the 228th ECS Meeting. This year’s program will be focused around solar critical issues and renewable energy. One of the invited talks is from the Joint Center for Artificial Photosynthesis (JCAP).

JCAP is pioneering revolutionary methods of synthesizing transportation fuels simply by combining three of Earth’s most abundant resources: carbon dioxide, water, and sunlight.

The goal is to generate liquid hydrocarbon or alcohol fuel products whose heating value equals or exceeds that of methanol, using selective and efficient chemical pathways.

Achieving a Technological Breakthrough

Any technological breakthrough of this sort requires multiple simultaneous advances in mechanisms, materials, and components—from novel catalysts and protection coatings to concepts for self-sustaining integrated systems—and JCAP, under its five-year renewal project, will continue to act as a hub for accelerated discovery and integration of these developments.

The project’s first two years will focus on an accelerated campaign of discovery and development, while years three to five will see a ramped-up emphasis on the integration of JCAP’s materials, catalytic mechanisms, and testbeds with advances made by JCAP, in close consultation and collaboration with the broader scientific community and industry.


ECS’s Nate Lewis is propelling his vision of efficient and affordable alternative energy sources with the new development of an “artificial leaf” system that splits water through solar energy to create hydrogen fuel.

(PS: Make sure to catch Nate Lewis’ presentation this October at the fifth international Electrochemical Energy Summit held during the 228th ECS Meeting!)

“This new system shatters all of the combined safety, performance, and stability records for artificial leaf technology by factors of 5 to 10 or more,” says Lewis, a 33-year ECS member and scientific director of the Joint Center for Artificial Photosynthesis.

Shattering Water Splitting Records

He and his team, including postdoctoral scholar and ECS member Ke Sun, were able to achieve recording-setting outcomes through the development of a advice with three novel components: two electrodes, one photoanode and one photocathode, and a membrane.

This from Futurity:

The photoanode uses sunlight to oxidize water molecules, generating protons and electrons as well as oxygen gas. The photocathode recombines the protons and electrons to form hydrogen gas.



Small-scale device provides easy “plug-and-play” testing of molecules and materials for artificial photosynthesis and fuel cell technologies.
Image: Joint Center for Artificial Photosynthesis

Scientists have developed a small-scale device that can aid in the advancement of artificial photosynthesis and fuel cell technologies.

The new device provides an easy “plug-and-play” microfluidic test-bed to evaluate materials for electrochemical energy conversion systems. Researchers will now be able to test small amounts of molecules and materials before producing a full-scale device to insure new devices will provide high energy density.

Sophia Haussener and Joel Ager, published ECS authors and past members, were two of the researchers that worked on the project for the U.S. Department of Energy. (Check out Haussener’s past research on photoelectrochemical water-splitting and Ager’s work in electron diffraction.)

This from U.S. Department of Energy:

As all functional components in this microfluidic test-bed can be easily exchanged, the performance of various components in the integrated system can be quickly assessed and tailored for optimization. The initial experiments and modeling were performed for water electrolysis; however, the system can be readily adapted to study proposed artificial photosynthesis and fuel cell technologies.

Read the full article here.

The researchers believe that this technology will be easily adaptable to other technologies, such as solar-fuel generators. Development of such devices may significantly accelerate due to the new ability to assess performance at an early stage.