Solar Energy

A spectrum of possibilities: insights into the evolution of far-red light photosynthesis

Published

1 year ago

November 29, 2023

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A spectrum of possibilities: insights into the evolution of far-red light photosynthesis

by Staff Writers

London, UK (SPX) Nov 29, 2023

A collaborative study led by Dr. Christopher Gisriel at Yale University and Dr. Tanai Cardona at Queen Mary University of London, published in Frontiers in Plant Science, offers new insight on the origin and evolution of a unique type of photosynthesis that enables some bacteria, specifically cyanobacteria, to harness far-red light.

Far-red light, which falls between 700 to 800 nanometers (nm), hardly visible to the human eye, is beyond the range typically used for photosynthesis because it contains lower energy than the standard visible range between blue and red (400 to 700 nm). The study’s insights into cyanobacteria’s ability to use far-red light are crucial, as they could provide conceptual frameworks to engineer enhanced plants with expanded light absorption capabilities for applications in biotech and agriculture.

The study’s findings not only shed light on the evolutionary journey of far-red photosynthesis but also hold profound implications for our understanding of life in the cosmos. M-dwarf stars, the most common type of star in the universe, emit far more far-red light than visible light, making them potential havens for far-red photosynthesis. If life can thrive on planets orbiting these stars, it could expand the boundaries of our search for extraterrestrial life.

The researchers’ analysis indicates that the ability to use far-red light evolved in two distinct stages. An early stage that involved cyanobacteria innovating a new pigment, chlorophyll f, enabling the photosystem to harvest far-red light for the first time. In addition, they developed a modified photosystem that could use this pigment to power the oxygen release reaction using only the lower energy red light. This stage possibly occurred in ancestral cyanobacteria forms and might have started as early as 3 billion years ago.

The late stage, occurring approximately 2 billion years ago, further optimized the capacity to harvest far-red light by evolving a second modified photosystem incorporating chlorophyll f at critical locations. This phase coincided with the diversification of cyanobacteria into the lineages existing today.

Significantly, the study also found evidence suggesting that far-red light photosynthesis can be gained by a cyanobacterium through horizontal gene transfer. This discovery indicates that the complex trait could be introduced viably into a photosynthetic organism not previously adapted to use far-red light.

The research underscores the intricate and adaptive nature of photosynthetic systems and opens new horizons for understanding how organisms evolve to harness energy efficiently in varying environmental conditions. The study also lays the groundwork for future explorations into optimising light use in biotech and agriculture, which could lead to algae strains or crop improvements in less-than-ideal light conditions.

Research Report:Molecular diversity and evolution of far-red light-acclimated photosystem I

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Solar Energy

Buried interface engineering drives advances in tin-lead perovskite solar cell efficiency

Published

2 days ago

December 20, 2024

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Buried interface engineering drives advances in tin-lead perovskite solar cell efficiency

by Simon Mansfield

Sydney, Australia (SPX) Dec 20, 2024

A team led by Prof. Meng Li from Henan University’s School of Nanoscience and Materials Engineering has unveiled an innovative approach to overcoming stability and efficiency challenges in tin-lead (Sn-Pb) perovskite solar cells. The researchers’ work focuses on optimizing the buried hole-selective interface using a specially designed self-assembled material, offering major implications for single-junction and tandem solar cell technologies.

Tin-lead perovskites are valued for their narrow bandgap properties, which position them as key materials for producing high-efficiency solar cells. However, energy level mismatches and degradation at the buried interface have constrained both their performance and long-term stability. Addressing these issues, Prof. Meng’s team designed a boronic acid-anchored hole-selective contact material, 4-(9H-carbazole-9-yl)phenylboronic acid (4PBA).

Compared to conventional materials, 4PBA demonstrated superior stability and compatibility at the substrate surface. Its high adsorption energy of -5.24 eV and significant molecular dipole moment (4.524 D) improved energy level alignment between the substrate and perovskite layer, facilitating efficient charge extraction. Additionally, the interface engineered using 4PBA improved perovskite crystallization and substrate contact, reducing defects and non-radiative recombination.

These advancements enabled Sn-Pb perovskite solar cells incorporating 4PBA to achieve a power conversion efficiency (PCE) of 23.45%. The material’s reduced corrosiveness also mitigated the degradation effects typically caused by PEDOT:PSS, a widely used hole-transport material, enhancing chemical stability and storage durability. The cells retained 93.5% of their initial efficiency after 2,000 hours of shelf storage.

“This approach offers a practical path to enhancing both the efficiency and stability of Sn-Pb perovskite solar cells, addressing energy level mismatches and interfacial stability concerns,” the research team commented.

The findings provide a foundation for advancing efficient and stable Sn-Pb perovskite solar cells and highlight the importance of interface engineering in next-generation photovoltaic technologies.

Research Report:Buried Hole-Selective Interface Engineering for High-Efficiency Tin-Lead Perovskite Solar Cells with Enhanced Interfacial Chemical Stability

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Solar Energy

New solar material advances green hydrogen production

Published

2 days ago

December 20, 2024

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New solar material advances green hydrogen production

by Simon Mansfield

Sydney, Australia (SPX) Dec 20, 2024

Researchers in nano-scale chemistry have made a significant stride in advancing the sustainable and efficient production of hydrogen from water using solar energy.

A collaborative international study led by Flinders University, with partners in South Australia, the US, and Germany, has identified a novel solar cell process that could play a crucial role in photocatalytic water splitting for green hydrogen production.

The research introduces a new class of kinetically stable ‘core and shell Sn(II)-perovskite’ oxide solar material. Paired with a catalyst developed by US researchers under Professor Paul Maggard, this material shows potential as a catalyst for the essential oxygen evolution reaction, a key step in generating pollution-free hydrogen energy.

The findings, published in The Journal of Physical Chemistry C, offer new insights into the development of carbon-free hydrogen technologies, leveraging renewable and greenhouse-gas-free power sources for high-performing and cost-effective electrolysis processes.

“This latest study is an important step forwards in understanding how these tin compounds can be stabilised and effective in water,” said Professor Gunther Andersson, lead author from the Flinders Institute for Nanoscale Science and Technology.

Professor Paul Maggard, from Baylor University, added, “Our reported material points to a novel chemical strategy for absorbing the broad energy range of sunlight and using it to drive fuel-producing reactions at its surfaces.”

Tin and oxygen compounds like those used in the study are already applied in diverse fields such as catalysis, diagnostic imaging, and therapeutic drugs. However, Sn(II) compounds are typically reactive with water and dioxygen, limiting their technological potential.

Global solar photovoltaic research continues to focus on developing cost-effective, high-performance perovskite-based systems as alternatives to conventional silicon and other existing technologies.

Hydrogen, often touted as a clean fuel, can be produced through various processes, including electrolysis powered by renewable energy, thermochemical water splitting using concentrated solar power, or waste heat from nuclear reactors. While fossil fuels and biomass can also generate hydrogen, the environmental and energy efficiency depends largely on the production method.

Solar-driven hydrogen production, which uses light to initiate the process, is emerging as a promising alternative for industrial-scale hydrogen generation.

This study builds on earlier research led by Professor Maggard, initially at North Carolina State University and now at Baylor University, and includes contributions from University of Adelaide experts such as Professor Greg Metha and collaborators from Universitat Munster in Germany. Professor Metha’s work explores the photocatalytic activity of metal clusters on oxide surfaces for reactor technologies.

Research Report:Chemical and Valence Electron Structure of the Core and Shell of Sn(II)-Perovskite Oxide Nanoshells

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Solar Energy

University of Houston scientists solving meteorological mysteries on Mars

Published

2 days ago

December 20, 2024

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University of Houston scientists solving meteorological mysteries on Mars

by Bryan Luhn for UH News

Houston TX (SPX) Dec 20, 2024

A groundbreaking achievement by scientists at the University of Houston is changing our understanding of climate and weather on Mars and providing critical insights into Earth’s atmospheric processes as well.

The study, led by Larry Guan, a graduate student in the Department of Physics at UH’s College of Natural Sciences and Mathematics, under the guidance of his advisors, Professor Liming Li from the Department of Physics and Professor Xun Jiang from the Department of Earth and Atmospheric Sciences and several world-renowned planetary scientists, generated the first-ever meridional profile of Mars’ radiant energy budget, or REB, which represents the balance or imbalance between absorbed solar energy and emitted thermal energy across the latitudes. On a global scale, an energy surplus leads to global warming, while a deficit results in global cooling. Furthermore, the meridional profile of Mars’ REB fundamentally influences weather and climate patterns on the red planet.

The findings are in a new paper just published in AGU Advances and will be featured in AGU’s prestigious science magazine EOS.

“The work in establishing Mars’ first meridional radiant energy budget profile is noteworthy,” Guan said. “Understanding Earth’s large-scale climate and atmospheric circulation relies heavily on REB profiles, so having one for Mars allows critical climatological comparisons and lays the groundwork for Martian meteorology.”

The profile, based on long-term observations from orbiting spacecraft, offers a detailed comparison of Mars’ REB to that of Earth, uncovering striking differences in the way each planet receives and radiates energy. While Earth exhibits an energy surplus in the tropics and a deficit in the polar regions, Mars displays the opposite configuration.

“On Earth, the tropical energy surplus drives warming and upward atmospheric motion, while the polar energy deficit causes cooling and downward atmospheric motion,” Jiang explained. “These atmospheric motions significantly influence weather and climate on our home planet. However, on Mars, we observe a polar energy surplus and a tropical energy deficit.”

That surplus, Guan says, is especially pronounced in Mars’ southern hemisphere during spring, playing a critical role in driving the planet’s atmospheric circulation and triggering global dust storms, the most prominent feature of Martian weather. These massive storms, which can envelop the entire planet, significantly alter the distribution of energy, providing a dynamic element that affects Mars’ weather patterns and climate.

“The interaction between dust storms and the REB, as well as with polar ice dynamics, brings to light the complex feedback processes that likely shape Martian weather patterns and long-term climate stability,” Guan said.

Earth’s global-scale energy imbalance has been recently discovered, which significantly contributes to global warming at a magnitude comparable to that caused by increasing greenhouse gases. Mars presents a distinct environment due to its thinner atmosphere and lack of anthropogenic effects. The research team is now examining potential long-term energy imbalances on Mars and their implications for the planet’s climate evolution.

“The REB difference between the two planets is truly fascinating, so continued monitoring will deepen our understanding of Mars’ climate dynamics,” Li said. “This research not only deepens our knowledge of the red planet but also provides critical insights into planetary atmospheric processes.”

Research Report:Distinct Energy Budgets of Mars and Earth