Solar Energy

Buckyballs on DNA for harvesting light

Published

4 years ago

February 24, 2021

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Organic molecules that capture photons and convert these into electricity have important applications for producing green energy. Light-harvesting complexes need two semiconductors, an electron donor and an acceptor. How well they work is measured by their quantum efficiency, the rate by which photons are converted into electron-hole pairs.

Quantum efficiency is lower than optimal if there is “self-quenching”, where one molecule excited by an incoming photon donates some of its energy to an identical non-excited molecule, yielding two molecules at an intermediate energy state too low to produce an electron-hole pair. But if electron donors and acceptors are better spaced out, self-quenching is limited, so that quantum efficiency improves.

In a new paper in Frontiers in Chemistry, researchers from the Karlsruhe Institute of Technology (KIT) synthesize a novel type of organic light-harvesting supramolecule based on DNA. The double helix of DNA acts as a scaffold to arrange chromophores (i.e. fluorescent dyes) – which function as electron donors – and “buckyballs” – electron acceptors – in three dimensions to avoid self-quenching.

“DNA is an attractive scaffold for building light-harvesting supramolecules: its helical structure, fixed distances between nucleobases, and canonical base pairing precisely control the position of the chromophores. Here we show that carbon buckyballs, bound to modified nucleosides inserted into the DNA helix, greatly enhance the quantum efficiency. We also show that the supramolecule’s 3D structure persists not only in the liquid phase but also in the solid phase, for example in future organic solar cells,” says lead author Dr Hans-Achim Wagenknecht, Professor for Organic Chemistry at Karlsruhe Institute of Technology (KIT).

DNA provides regular structure, like beads on a helical string

As scaffold, Wagenknecht and colleagues used single-stranded DNA, deoxyadenosine (A) and thymine (T) strands 20 nucleotides long. This length was chosen because theory suggests that shorter DNA oligonucleotides wouldn’t assemble orderly, while longer ones wouldn’t be soluble in water.

The chromophores were violet-fluorescent pyrene and red-fluorescent Nile red molecules, each bound noncovalently to a single synthetic uracil (U)-deoxyribose nucleoside. Each nucleoside was base-paired to the DNA scaffold, but the order of pyrenes and Nile reds was left to chance during self-assembly.

For the electron acceptors, Wagenknecht et al. tested two forms of “buckyballs” – also called fullerenes – which are known to have an excellent capacity for “quenching” (accepting electrons). Each buckyball was a hollow globe built from interlocking rings of five or six carbon atoms, for a total of 60 carbons per molecule. The first form of buckyball tested binds nonspecifically to the DNA through electrostatic charges.

The second form – not previously tested as an electron acceptor – was covalently bound via a malonic ester to two flanking U-deoxyribose nucleosides, which allowed it to be base-paired to an A nucleotide on the DNA.

High quantum efficiency, including in solid phase

The researchers confirmed experimentally that the 3D structure of the DNA-based supramolecule persists in solid phase: a crucial requirement for applications in solar cells. To this end, they tested supramolecules with either form of buckyballs as the active layer in a miniature solar cell.

The constructs showed excellent charge separation – the formation of a positive hole and negative electron charge in the chromophore and their acceptance by nearby buckyballs – with either form of buckyball, but especially for the second form.

The authors explain this from the more specific binding, through canonical base-pairing, to the DNA scaffold by the second form, which should result in a smaller distance between buckyball and chromophore. This means that the second form is the better schoice for use in solar cells.

Importantly, the authors also show that the DNA-dye-buckyball supramolecule has strong circular dichroism, that is, it is much more reactive to left- than to right-handed polarized light, due to its complex 3D helical structure – even in the solid phase.

“”I don’t expect that everyone will have solar cells with DNA on their roof soon. But the chirality of DNA will be interesting: DNA-based solar cells might sense circularly polarized light in specialized applications,” concludes Wagenknecht.

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Solar Energy

Argonne to lead National Energy Storage Research Hub

Published

2 days ago

September 6, 2024

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Argonne to lead National Energy Storage Research Hub

by Clarence Oxford

Los Angeles CA (SPX) Sep 05, 2024

The U.S. Department of Energy (DOE) has selected Argonne National Laboratory to lead the newly established Energy Storage Research Alliance (ESRA), a national hub focused on advancing energy storage technologies. The ESRA, co-led by DOE’s Lawrence Berkeley National Laboratory (Berkeley Lab) and Pacific Northwest National Laboratory (PNNL), is one of two new Energy Innovation Hubs announced by the DOE.

Bringing together nearly 50 leading researchers from three national laboratories and 12 universities, ESRA aims to address the most critical challenges in battery technology, such as safety, high-energy density, and the development of long-duration storage solutions using cost-effective and abundant materials. The initiative is designed to push the boundaries of energy storage science, fostering innovation and strengthening the competitive edge of the U.S. in this crucial field.

“The demand for high-performance, low-cost and sustainable energy storage devices is on the rise, especially those with potential to deeply decarbonize heavy-duty transportation and the electric grid,” stated Shirley Meng, ESRA director and chief scientist at the Argonne Collaborative Center for Energy Storage Science. “To achieve this, energy storage technology must reach levels of unprecedented performance, surpassing the capabilities of current lithium-ion technology. The key to making these transformative leaps lies in a robust research and development initiative firmly grounded in basic science.”

Leveraging decades of investment in fundamental science, ESRA will focus on transformative discoveries in materials chemistry, a deeper understanding of electrochemical processes at the atomic level, and establishing the scientific foundations necessary for major advancements in energy storage technology.

“ESRA creates an energy storage research ecosystem with the mission to rapidly innovate, shorten the time between basic discovery and technology development, and train the next-generation workforce,” commented Bryan McCloskey, ESRA deputy director for scientific thrusts and a faculty engineer at Berkeley Lab.

The success of ESRA’s efforts will lead to the development of high-energy batteries that are fire-resistant, capable of providing long-duration storage for multiple days, have a lifespan of several decades, and are constructed from low-cost, widely available materials.

“ESRA will pave the way for innovative energy storage solutions that drive both U.S. prosperity and security,” said Argonne Director Paul Kearns. “As the lead laboratory for ESRA under the Department of Energy’s Office of Science, Argonne takes pride in spearheading this collaborative effort that unites world-leading experts and taps the impressive scientific resources available in national labs and academia.”

The DOE has committed up to $62.5 million in funding for ESRA over the next five years.

In addition to its research goals, the Argonne-led hub will prioritize training a diverse, next-generation battery workforce to meet future manufacturing demands. This will be achieved through innovative training programs that involve industry, academia, and government partnerships.

“Cultivating a diverse workforce dedicated to safeguarding America’s energy resilience is key to ESRA’s mission,” noted Wei Wang, ESRA deputy director for crosscuts and director of the Energy Storage Materials Initiative at PNNL. “Through our strategic equity and inclusion initiatives, we plan to create a robust training ground for energy storage science from the undergraduate to postdoctoral levels.”

With Berkeley Lab and PNNL as co-leads, the ESRA collaboration brings together comprehensive expertise across the energy storage spectrum. Their state-of-the-art capabilities in technology discovery, modeling and simulation, and materials synthesis and characterization complement those of Argonne, setting the stage for significant advancements in energy storage.

Argonne is joined by 14 partners in this initiative, all of whom are deeply involved in ESRA’s scientific endeavors, governance, strategic development, and the training of the next generation of battery scientists and engineers. This collaboration among national laboratories and universities is vital for discovering new materials, accelerating the development of technology, and commercializing new energy storage innovations.

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Solar Energy

UN’s Guterres says China-Africa ties can drive ‘renewable energy revolution’

Published

2 days ago

September 6, 2024

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UN’s Guterres says China-Africa ties can drive ‘renewable energy revolution’

by AFP Staff Writers

Beijing (AFP) Sept 5, 2024

United Nations Secretary-General Antonio Guterres told African leaders Thursday that expanding ties between China and the continent could “drive the renewable energy revolution”.

Guterres and more than 50 African leaders are attending this week’s China-Africa forum, according to state media.

Guterres told the gathering that “China’s remarkable record of development — including on eradicating poverty — provides a wealth of experience and expertise”.

“It can be a catalyst for key transitions on food systems and digital connectivity,” he said.

“And as home to some of the world’s most dynamic economies, Africa can maximise the potential of China’s support in areas from trade to data management, finance and technology,” Guterres added.

Guterres also told the leaders it was time to correct “historic injustices” against the continent.

“It is outrageous… that the continent of Africa has no permanent seat on the Security Council,” he said.

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Solar Energy

Major Qatari plant to double solar capacity by 2030: minister

Published

6 days ago

September 2, 2024

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Major Qatari plant to double solar capacity by 2030: minister

by AFP Staff Writers

Doha (AFP) Sept 1, 2024

A large new solar plant planned in Qatar will double the Gulf emirate’s previously projected renewable energy capacity by 2030, Qatari Energy Minister Saad al-Kaabi announced on Sunday.

The photovoltaic farm, which will be built in the Dukhan area some 80 kilometres (50 miles) west of the capital Doha, will increase the gas-rich state’s solar production capacity to four gigawatts by the end of the decade, Kaabi said.

The plant “that will be established in Dukhan area will produce 2,000 megawatts, which is twice more than the capacity of Qatar’s production of solar energy of the current projects,” the minister, who is also chief executive of state-owned QatarEnergy, said.

In October 2022, Qatar inaugurated its first large-scale solar farm at al-Kharsaah, west of Doha. The emirate announced in August of the same year another solar project with two plants at Ras Laffan in the north.

Through the combined projects, including at Dukhan, Qatar would achieve “4,000 megawatts of clean energy by 2030”, Kaabi said.

This will “constitute 30 percent of the total production of energy of the state of Qatar” with a yearly reduction of “4.7 million tonnes of CO2 emissions,” he added.

Kaabi said the existing projects should produce 1.7 gigawatts of energy “in first quarter of next year, or early next year”.

The energy minister also announced plans to more than double Qatar’s urea production making the country the largest producer of the fertiliser in the world by the end of the decade.

He said Qatar would “maximise the production of chemical fertilisers” through “a complex with global standards” which would “increase our production capacity from 6 million tonnes annually to more than 12.4 million tonnes annually”.

Qatar is one of the world’s top liquefied natural gas producers alongside the United States, Australia and Russia. Natural gas is a major ingredient in urea manufacturing.

In February, Qatar announced plans to expand its output from its North Field project, saying it will boost capacity to 142 million tonnes per year before 2030.

Over the past year, Qatar has inked a series of long-term LNG deals with France’s Total, Britain’s Shell, India’s Petronet, China’s Sinopec and Italy’s Eni among others.

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QatarEnergy

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