Scientists pioneer a new way to turn sunlight into fuel

hll43 — Mon, 03 Sep 2018 15:00:00 +0000

Photosynthesis is the process plants use to convert sunlight into energy. Oxygen is produced as a by-product of photosynthesis when the water absorbed by plants is ‘split’. It is one of the most important reactions on the planet because it is the source of nearly all of the world’s oxygen. Hydrogen which is produced when the water is split could potentially be a green and unlimited source of renewable energy.

A new study, led by academics at the ̽��ֱ�� of Cambridge, used semi-artificial photosynthesis to explore new ways to produce and store solar energy. They used natural sunlight to convert water into hydrogen and oxygen using a mixture of biological components and manmade technologies.

̽��ֱ��research could now be used to revolutionise the systems used for renewable energy production. A new paper, published in Nature Energy, outlines how academics at the Reisner Laboratory in Cambridge's Department of Chemistry developed their platform to achieve unassisted solar-driven water-splitting.

Their method also managed to absorb more solar light than natural photosynthesis.

Katarzyna Sokół, first author and PhD student at St John’s College, said: “Natural photosynthesis is not efficient because it has evolved merely to survive so it makes the bare minimum amount of energy needed – around 1-2 per cent of what it could potentially convert and store.”

Artificial photosynthesis has been around for decades but it has not yet been successfully used to create renewable energy because it relies on the use of catalysts, which are often expensive and toxic. This means it can’t yet be used to scale up findings to an industrial level.

̽��ֱ��Cambridge research is part of the emerging field of semi-artificial photosynthesis which aims to overcome the limitations of fully artificial photosynthesis by using enzymes to create the desired reaction.

Sokół and the team of researchers not only improved on the amount of energy produced and stored, they managed to reactivate a process in the algae that has been dormant for millennia.

She explained: “Hydrogenase is an enzyme present in algae that is capable of reducing protons into hydrogen. During evolution, this process has been deactivated because it wasn’t necessary for survival but we successfully managed to bypass the inactivity to achieve the reaction we wanted – splitting water into hydrogen and oxygen.”

Sokół hopes the findings will enable new innovative model systems for solar energy conversion to be developed.

She added: “It’s exciting that we can selectively choose the processes we want, and achieve the reaction we want which is inaccessible in nature. This could be a great platform for developing solar technologies. ̽��ֱ��approach could be used to couple other reactions together to see what can be done, learn from these reactions and then build synthetic, more robust pieces of solar energy technology.”

This model is the first to successfully use hydrogenase and photosystem II to create semi-artificial photosynthesis driven purely by solar power.

Dr Erwin Reisner, Head of the Reisner Laboratory, a Fellow of St John’s College, ̽��ֱ�� of Cambridge, and one of the paper’s authors described the research as a ‘milestone’.

He explained: “This work overcomes many difficult challenges associated with the integration of biological and organic components into inorganic materials for the assembly of semi-artificial devices and opens up a toolbox for developing future systems for solar energy conversion.”

Reference:
Katarzyna P. Sokół et al. 'Bias-free photoelectrochemical water splitting with photosystem II on a dye-sensitized photoanode wired to hydrogenase.' Nature Energy (2018). DOI: 10.1038/s41560-018-0232-y

Originally published on the St John's College website.

̽��ֱ��quest to find new ways to harness solar power has taken a step forward after researchers successfully split water into hydrogen and oxygen by altering the photosynthetic machinery in plants.

This could be a great platform for developing solar technologies.

Katarzyna Sokół

Experimental two-electrode setup showing the photoelectrochemical cell illuminated with simulated solar light

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New lab to focus on creating sustainable energy source

gm349 — Fri, 27 Apr 2012 11:42:59 +0000

A state-of-the-art laboratory, which aims to use sunlight to power the sustainable conversion of CO₂ and water to form syngas, a high-energy gas mixture with potential as a future fuel source, opened this week in the Department of Chemistry.

̽��ֱ��Christian Doppler laboratory for Sustainable SynGas Chemistry will address application-oriented basic research questions to facilitate the creation of a sustainable carbon-based economy. It is jointly funded by the Austrian Christian Doppler Research Association (Federal Ministry of Economy, Family and Youth & the National Foundation for Research, Technology and Development) and the OMV Group for a period of seven years.

̽��ֱ��lab will research ways to use light from the sun to power the sustainable conversion of the greenhouse gas carbon dioxide and water to form syngas, a high-energy gas mixture containing hydrogen, H₂ (an attractive fuel on its own), and carbon monoxide, CO. Syngas is a valuable gas mixture and, importantly, it can be transformed into liquid hydrocarbons ('gasoline'), also known as liquid fuels.

Despite its potential as a future fuel source, syngas is already used as an invaluable chemical feedstock for the petrochemical industry, as an intermediate for the production of many chemicals such as H₂, methanol and ammonia. Unfortunately, current production of syngas is non-renewable; it is produced on a mega-ton scale by the energy-intensive steam reforming of fossil fuels, and subsequent H₂ to CO ratio adjustment by the water-gas shift reaction. This unsustainable process yields fuel cell grade H₂ and the greenhouse gas CO₂.

Dr Erwin Reisner, Head of the Christian Doppler Laboratory, said: “ ̽��ֱ��approach of the new laboratory aims to develop the basic principles to allow for a renewable production of syngas. Our long-term vision is a transition from a fossil-based to a sustainable carbon-based economy.”

̽��ֱ��CD-laboratory will focus on developing molecular catalysts, which will ultimately be integrated in nanostructured materials for syngas generation. This approach will allow for the assembly of a small-scale device for solar syngas production. ̽��ֱ��CD-laboratory will operate with an exceptional cross-disciplinary approach at the interface of bio-inspired molecular and materials synthesis, advanced electrochemistry, photochemistry and nanodevice engineering. ̽��ֱ��proposed research project combines a high degree of novelty with potentially enormous impact on academic science, industry and society.

̽��ֱ��Christian Doppler Research Association is a non-profit organization that supports basic science and technology to economically relevant questions. ̽��ֱ��OMV Group is an Austrian-based oil refining company with important global activities.

Research will explore using sunlight to convert greenhouse gas carbon dioxide and water to syngas, the precursor to liquid fuel.

̽��ֱ��approach of the new laboratory aims to develop the basic principles to allow for a renewable production of syngas. Our long-term vision is a transition from a fossil-based to a sustainable carbon-based economy.

Dr Erwin Reisner, Head of the Christian Doppler Laborator

Skyseeker from Flickr

Sun

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̽��ֱ�� of Cambridge - sunlight

Scientists pioneer a new way to turn sunlight into fuel

New lab to focus on creating sustainable energy source