GT/ Low-energy process for high-performance solar cells

Paradigm
Paradigm
Published in
25 min readMay 17, 2024

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Energy & green technology biweekly vol.69, 30th April — 17th May

TL;DR

  • Perovskite solar cells have emerged as a promising alternative to conventional, silicon solar cells, boasting a number of advantages. But processing the material has been a complicated affair. Now, researchers have developed a method to make high-quality perovskite films at room temperature. The team’s innovation not only simplified the production process but also increased the material’s efficiency from under 20% to 24.4%.
  • Charge-recharge cycling of lithium-superrich iron oxide, a cost-effective and high-capacity cathode for new-generation lithium-ion batteries, can be greatly improved by doping with readily available mineral elements.
  • Researchers have developed a chemical process using plasma that could create sustainable jet fuel from methane gas emitted from landfills, potentially creating a low-carbon aviation industry.
  • Researchers have devised a smart approach to optimize solar energy effectiveness. Their innovative method includes incorporating artificial ground reflectors, a simple yet powerful enhancement.
  • The use of femtosecond lasers to form glass-to-glass welds for solar modules would make the panels easier to recycle, according to a proof-of-concept study.
  • Interactions between wind turbines could reduce power output by 30% in proposed offshore wind farm areas along the East Coast, new research has found.
  • A team of researchers has made a significant breakthrough in the field of organic photovoltaics.
  • A method has been discovered to treat water heavily contaminated with unhealthful forever chemicals, known by chemists as PFAS or poly- and per-fluoroalkyl substances. It involves treating heavily contaminated water with ultraviolet (UV) light, sulfite, and a process called electrochemical oxidation.
  • Researchers report a new method that reduces the amount of iridium needed to produce hydrogen from water by 95%, without altering the rate of hydrogen production.
  • Countries with limited potential for renewables could save up to 20% of costs for green steel and up to 40% for green chemicals from green hydrogen if they relocated their energy-intensive production and would import from countries where renewable energy is cheaper, according to a new study shows.
  • And more!

Green Technology Market

Green technology is an applicable combination of advanced tools and solutions to conserve natural resources and environment, minimize or mitigate negative impacts from human activities on the environment, and ensure sustainability development. Green technology is also referred to as clean technology or environmental technology which includes technologies, such as IoT, AI, analytics, blockchain, digital twin, security, and cloud, which collect, integrate, and analyze data from various real-time data sources, such as sensors, cameras, and Global Positioning System (GPS).

Green technology, also known as sustainable technology, protects the environment by using various forms of sustainable energy. Some of the best examples of green technologies include solar panels, LED lighting, wind energy, electric vehicles, vertical farming, and composting.

The global Green Technology and Sustainability market size to grow from USD 11.2 billion in 2020 to USD 36.6 billion by 2025, at a Compound Annual Growth Rate (CAGR) of 26.6% during the forecast period. The growing consumer and industrial interest for the use of clean energy resources to conserve environment and increasing use of Radio Frequency Identification sensors across industries are driving the adoption of green technology and sustainability solutions and services in the market.

Latest Research

Room-temperature-processed perovskite solar cells surpassing 24% efficiency

by Ahra Yi, Sangmin Chae, Hoang Mai Luong, Sung Hun Lee, Hanbin Lee, Haeun Yoon, Do-Hyung Kim, Hyo Jung Kim, Thuc-Quyen Nguyen in Joule

Finding reliable, eco-friendly power sources is crucial as our world grapples with increasing energy needs and the urgent call to combat climate change. Solar energy offers one solution, with scientists devising ever more efficient materials for capturing sunlight.

Perovskite solar cells have emerged as a promising alternative to conventional, silicon solar cells, boasting a number of advantages. But processing the material has been a complicated affair. Now, researchers at UC Santa Barbara have developed a method to make high-quality perovskite films at room temperature. The team’s innovation not only simplified the production process but also increased the material’s efficiency from under 20% to 24.4%.

Perovskite is a class of materials characterized by its specific crystal structure, exemplified by the mineral of the same name. Solar cells made from this material boast many advantages compared to silicon-based solar cells. They’re lightweight, flexible and can be applied as a spray or printed like ink. Perovskite solar cell production also has the potential for a smaller carbon footprint than silicon photovoltaics, which require high temperatures and a cleanroom environment.

That said, producing these cells involves high-temperature annealing and tricky post-treatment steps, significantly slowing fabrication and making it hard to incorporate them into everyday items. These factors impede perovskite’s adoption in large-scale manufacturing and make them less environmentally friendly.

By fine tuning the material’s chemical composition, the authors developed a perovskite ink that created high-quality films much more effectively. “Our method follows the same procedures as the conventional one, except for omitting the two most time-consuming steps: thermal annealing and post-treatment,” said co-lead author Ahra Yi, a postdoctoral researcher at UC Santa Barbara. The simpler fabrication technique also meshes better with standard manufacturing processes and reduces the overall energy use, which lowers its carbon dioxide emissions.

A thin perovskite film coats a fresh leaf. Photo Credit Ahra Yi and Sangmin Chae et al.

What’s more, the new material outperformed cells made using the high-temperature process. “Our optimized perovskite solar cell achieved a remarkable efficiency of 24.4%,” said co-lead author and UCSB doctoral student Sangmin Chae, “surpassing previous limits, which were below 20% for room-temperature processed devices.”

The new procedure is also extremely gentle. To demonstrate this, the team prepared a perovskite layer on fresh leaves, a feat that was impossible with the previous, high-temperature process.

“We thought this choice would be both eye-catching and symbolic, since solar cells mimic the photosynthetic process in leaves,” said Yi.

Toward Cost-Effective High-Energy Lithium-Ion Battery Cathodes: Covalent Bond Formation Empowers Solid-State Oxygen Redox in Antifluorite-Type Lithium-Rich Iron Oxide

by Hiroaki Kobayashi, Yuki Nakamura, Yumika Yokoyama, Itaru Honma, Masanobu Nakayama in ACS Materials Letters

Charge-recharge cycling of lithium-superrich iron oxide, a cost-effective and high-capacity cathode for new-generation lithium-ion batteries, can be greatly improved by doping with readily available mineral elements.

The energy capacity and charge-recharge cycling (cyclability) of lithium-iron-oxide, a cost-effective cathode material for rechargeable lithium-ion batteries, is improved by adding small amounts of abundant elements. The development, achieved by researchers at Hokkaido University, Tohoku University, and Nagoya Institute of Technology.

Lithium-ion batteries have become indispensable in modern life, used in a multitude of applications including mobile phones, electric vehicles, and large power storage systems. A constant research effort is underway to increase their capacity, efficiency, and sustainability. A major challenge is to reduce the reliance on rare and expensive resources. One approach is to use more efficient and sustainable materials for the battery cathodes, where key electron exchange processes occur.

The researchers worked to improve the performance of cathodes based on a particular lithium-iron-oxide compound. In 2023, they reported a promising cathode material, Li5FeO4, that exhibits a high capacity using iron and oxygen redox reactions. However, its development encountered problems associated with the production of oxygen during charging-recharging cycling.

“We have now found that the cyclability could be significantly enhanced by doping small amounts of abundantly available elements such as aluminum, silicon, phosphorus, and sulfur into the cathode’s crystal structure,” says Associate Professor Hiroaki Kobayashi at the Department of Chemistry, Faculty of Science, Hokkaido University.

A crucial chemical aspect of the enhancement proved to be the formation of strong ‘covalent’ bonds between the dopant and oxygen atoms within the structure. These bonds hold atoms together when electrons are shared between the atoms, rather than the ‘ionic’ interaction between positive and negatively charged ions.

“The covalent bonding between the dopant and oxygen atoms makes the problematic release of oxygen less energetically favorable, and therefore less likely to occur,” says Kobayashi.

The researchers used X-ray absorption analysis and theoretical calculations to explore the fine details of changes in the structure of the cathode material caused by introducing different dopant elements. This allowed them to propose theoretical explanations for the improvements they observed. They also used electrochemical analysis to quantify the improvements in the cathode’s energy capacity, stability and the cycling between charging and discharging phases, showing an increase in capacity retention from 50% to 90%.

“We will continue to develop these new insights, hoping to make a significant contribution to the advances in battery technology that will be crucial if electric power is to widely replace fossil fuel use, as required by global efforts to combat climate change,” Kobayashi concludes.

The next phase of the research will include exploring the challenges and possibilities in scaling up the methods into technology ready for commercialization.

Long-Chain Hydrocarbons from Nonthermal Plasma-Driven Biogas Upcycling

by Josip Knezevic, Tianqi Zhang, Renwu Zhou, Jungmi Hong, et al in Journal of the American Chemical Society

In a world first, University of Sydney researchers have developed a chemical process using plasma that could create sustainable jet fuel from methane gas emitted from landfills, potentially creating a low-carbon aviation industry.

Methane is a far more potent greenhouse gas than carbon dioxide (CO2). According to the International Energy Agency, the concentration of methane in the atmosphere is currently around two-and-a-half times greater than pre-industrial levels and is increasing steadily, with waste emissions and the burning of fossil fuels accounting for a significant proportion.

Australia recently joined the international methane mitigation agreement with the United States, the European Union, Japan and the Republic of Korea.

Lead author, Professor PJ Cullen from the University of Sydney’s School of Chemical and Biomolecular Engineering and Net Zero Initiative said: “Globally, landfills are a major emitter of greenhouse gases, mainly a mixture of CO2 and methane. We have developed a process that would take these gases and convert them into fuels, targeting sectors that are difficult to electrify, like aviation.”

Schematic of the NTP reactor configuration employed. The plasma bubbles enable the conversion of CO2 and CH4 into solid long-chain hydrocarbons, liquid products, and gaseous products.

“Modern landfill facilities already capture, upgrade and combust their gas emissions for electricity generation, however, our process creates a much more environmentally impactful and commercially valuable product,” he said.

Global landfill emissions are estimated at 10–20 million tonnes of greenhouse gases per year, a value comparable to the emissions of the global energy sector.

Aviation currently accounts for approximately three percent of the world’s emissions. Creating a “closed loop” fuel based on existing emissions would eliminate the need for traditional and sustainable jet fuels, which add further emissions into the atmosphere. The process would work by extracting methane from a landfill site, known as a methane well, which uses a shaft-like mechanism to extract gases.

“The beauty of this is that this simple process captures almost the exact composition that we need for our process,” said Professor Cullen.

“Non-thermal plasma is an electricity-driven technology which can excite gas at both a low temperature and atmospheric pressure. Essentially, what this means is this approach facilitates the conversion of the gas into value-added products by inducing plasma discharge within forming gas bubbles. The process doesn’t require heat or pressure, meaning it requires less energy, making it highly compatible with renewable energy power sources.”

Artificial ground reflector size and position effects on energy yield and economics of single‐axis‐tracked bifacial photovoltaics

by Mandy R. Lewis, Silvana Ovaitt, Byron McDanold, Chris Deline, Karin Hinzer in Progress in Photovoltaics: Research and Applications

Solar energy is a crucial asset in the fight against climate change, and researchers at the University of Ottawa have devised a smart approach to optimize its effectiveness. Their innovative method includes incorporating artificial ground reflectors, a simple yet powerful enhancement.

The researchers found that by integrating these reflectors into solar setups, they could improve the system’s energy production and efficiency, making such projects more economically viable. This discovery is significant in assessing the costs and benefits of using artificial reflectors in solar energy ventures.

To study how reflective ground covers affect solar energy output, the University of Ottawa’s SUNLAB, led by electrical engineering Professor Karin Hinzer, who is also vice-dean, research of the Faculty of Engineering, collaborated with the National Renewable Energy Laboratory (NREL) in Golden, Colorado, a world leader in clean energy research, development, and deployment. The study, which was conducted by electrical engineering doctoral candidate Mandy Lewis in Golden, Colorado, found that placing reflective surfaces under solar panels can increase their energy output by up to 4.5%.

A) Photo of NREL’s bifacial experimental single-axis tracking (BEST) field with reflecting material installed (100% coverage case) and (B) measured spectral reflectivity of high-albedo material with photo of sample (inset).

“We found that highly reflective white surfaces can boost solar power output,” explains Mandy Lewis, the paper’s lead author. “Critically, these reflectors should be placed directly under the solar panels, not between rows, to maximize this benefit.”

These findings are particularly significant in Canada, where snow cover persists for three-to four months of the year in major cities like Ottawa and Toronto, and 65% of the country’s vast landmass experiences snow cover for over half the year. Bifacial solar systems, paired with high ground reflectivity, offer tremendous potential in these regions. Additionally, given that approximately 4% of the world’s land areas are classified as sandy deserts, this finding has global applications.

According to Lewis, “this research is crucial for maximizing solar energy production in geographically diverse locations. Furthermore, by generating more power per unit of land area, reflectors are ideal for densely populated areas, like city centres, where space limitations exist for solar installations.”

Towards Polymer-Free, Femto-Second Laser-Welded Glass/Glass Solar Modules

by David L. Young, Timothy J. Silverman, Nicholas P. Irvin, Daniel Huerta-Murillo, Bill Holtkamp, Nick Bosco in IEEE Journal of Photovoltaics

The use of femtosecond lasers to form glass-to-glass welds for solar modules would make the panels easier to recycle, according to a proof-of-concept study conducted by researchers at the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL).

The welds would eliminate the need for plastic polymer sheets that are now laminated into solar modules but make recycling more difficult. At the end of their useful lifespan, the modules made with the laser welds can be shattered. The glass and metal wires running through the solar cells can be easily recycled and the silicon can be reused.

“Most recyclers will confirm that the polymers are the main issue in terms of inhibiting the process of recycling,” said David Young, senior scientist and group manager for the High-Efficiency Crystalline Photovoltaics group in the Chemistry and Nanoscience department at NREL. Young is lead author of a new paper outlining the use of laser welds for solar modules.

The use of a laser to weld the edges of glass together can help make solar panels easier to recycle at the end of their lifespan. Graphic by Al Hicks

Written with NREL colleagues Tim Silverman, Nicholas Irvin, and Nick Bosco, the paper also counts as its coauthors two employees of Trumpf Inc., the California company that made the femtosecond laser involved. A femtosecond laser uses a short pulse of infrared light that melts the glass together to form a strong, hermetic seal.

The glass weld can be used on any type of solar technology — silicon, perovskites, cadmium telluride — because the heat of the weld is confined to a few millimeters from the laser focus.

Solar modules are made of semiconductors designed to capture a specific portion of the solar spectrum, harnessing sunlight to create electricity. Typically, the semiconductors are sandwiched between two sheets of glass laminated together with polymer sheets. NREL’s research showed that femtosecond laser, glass/glass welds are essentially as strong as the glass itself.

“As long as the glass doesn’t break, the weld is not going to break,” he said. “However, not having the polymers between the sheets of glass requires welded modules to be much stiffer. Our paper showed that with proper mounting and a modification to the embossed features of the rolled glass, a welded module can be made stiff enough to pass static load testing.”

NREL’s research is the first to use a femtosecond laser to form glass/glass welds for use in a module. A different type of edge sealing using nanosecond lasers and a glass frit filler was tried in the past, but the welds proved too brittle for use in outdoor module designs. The femtosecond laser welds offer superior strength with hermetic sealing at a compelling cost.

Young said the research is “definitely high risk, high reward,” but points to a direction for further research to extend the life of solar modules to beyond 50 years and to allow easier recycling.

Seasonal variability of wake impacts on US mid-Atlantic offshore wind plant power production

by David Rosencrans, Julie K. Lundquist, Mike Optis, Alex Rybchuk, Nicola Bodini, Michael Rossol in Wind Energy Science

As summer approaches, electricity demand surges in the U.S., as homes and businesses crank up the air conditioning. To meet the rising need, many East Coast cities are banking on offshore wind projects the country is building in the Atlantic Ocean.

For electric grid operators, knowing how much wind power these offshore turbines can harvest is critical, but making accurate predictions can be difficult. A team of scientists at the University of Colorado Boulder and their collaborators are working to tackle the challenge.

In a paper, a team led by Dave Rosencrans, a doctoral student, and Julie K. Lundquist, a professor in the Department of Atmospheric and Ocean Sciences, estimate that offshore wind turbines in the Atlantic Ocean region, where the U.S. plans to build large wind farms, could take away wind from other turbines nearby, potentially reducing the farms’ power output by more than 30%.

Accounting for this so-called “wake effect,” the team estimated that the proposed wind farms could still supply approximately 60% of the electricity demand of the New England grid, which covers Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont.

“The U.S. is planning to build thousands of offshore wind turbines, so we need to predict when those wakes will be expensive and when they have little effect,” said Lundquist, who is also a fellow at CU Boulder’s Renewable and Sustainable Energy Institute.

When wind passes through turbines, the ones at the front, or upstream, extract some energy from the wind. As a result, the wind slows down and becomes more turbulent behind the turbines. This means the turbines downstream get slower wind, sometimes resulting in lower power generation. The wake effect is particularly prominent offshore, because there are no houses or trees that stir up the air, which helps dissipate the wakes, said Rosencrans, the paper’s first author.

Using computer simulations and observational data of the atmosphere, the team calculated that the wake effect reduces total power generation by 34% to 38% at a proposed wind farm off the East Coast. Most of the reduction comes from wakes formed between turbines within a single farm. But under certain weather conditions, wakes could reach turbines as far as 55 kilometers downwind and affect other wind farms. For example, during hot summer days, the airflow over the cool sea surface tends to be relatively stable, causing wakes to persist for longer periods and propagate over longer distances.

“Unfortunately, summer is when there’s a lot of electrical demand,” Rosencrans said. “We showed that wakes are going to have a significant impact on power generation. But if we can predict their effects and anticipate when they are going to happen, then we can manage them on the electrical grid.”

In early 2024, five looming wind turbines off the coast of Massachusetts from the country’s first large-scale offshore wind project delivered the first batch of wind power to the New England grid. More turbines are under construction off the coasts of Rhode Island, Virginia and New York. The Biden Administration has set a goal to install 30 gigawatts of offshore wind capacity by 2030, which is enough to power more than 10 million homes for a year.

Compared with energy sources derived from fossil fuels, wind and solar power tend to be variable, because the sun doesn’t always shine and the wind doesn’t always blow. This variability creates a challenge for grid operators, said Lundquist. The power grid is a complex system that requires a perfect balance of supply and demand in real-time. Any imbalances could lead to devastating blackouts, like what happened in Texas in 2021 when power outages killed nearly 250 people. As the country continues to expand renewable energy projects and integrates more clean electricity into the power system, grid operators need to know precisely how much energy from each renewable source they can count on.

To better understand how the wind blows in the proposed wind farm area, Lundquist’s team visited islands off the New England coast and installed a host of instruments last December as part of the Department of Energy’s Wind Forecast Improvement Project 3. The project is a collaboration of researchers from CU Boulder, Woods Hole Oceanographic Institute and several other national laboratories.

The instruments, including weather monitors and radar sensors, will collect data for the next year or more. Previously, offshore wind power prediction models usually relied on intermittent data from ships and satellite observations. The hope is that with continuous data directly from the ocean, scientists can improve prediction models and better integrate more offshore wind energy into the grid.

In addition to the growing demand for air conditioning and heat pumps, electricity consumption in the U.S. has been rising rapidly in recent years because of the increasing prevalence of electric vehicles, data centers and manufacturing facilities. Over the next five years, analyses project that electricity demand in the U.S. will increase by nearly 5%, a substantial increase compared with the estimated annual growth rate of 0.5% over the past decade.

“We need a diverse mix of clean energy sources to meet the demand and decarbonize the grid,” Lundquist said. “With better predictions of wind energy, we can achieve more reliance on renewable energy.”

The role of interfacial donor–acceptor percolation in efficient and stable all-polymer solar cells

by Zhen Wang, Yu Guo, Xianzhao Liu, Wenchao Shu, Guangchao Han, Kan Ding, Subhrangsu Mukherjee, Nan Zhang, Hin-Lap Yip, Yuanping Yi, Harald Ade, Philip C. Y. Chow in Nature Communications

A team of researchers led by Professor Philip C.Y. Chow from the Department of Mechanical Engineering at the University of Hong Kong (HKU) has made a significant breakthrough in the field of organic photovoltaics. Their research paves the way for more sustainable and viable solar energy solutions for daily applications.

Organic photovoltaics (OPV), which employs cost-effective, printable, and environmentally friendly polymer semiconductors, holds tremendous potential for generating sustainable and renewable energy. However, due to the soft nature of polymers, achieving OPV devices with both high efficiency and long operation stability has been a long-standing research challenge.

The research team’s work has shed light on how to overcome this challenge. The team focused their research on a new type of electron-accepting molecule called Y6, which, when polymerised, has shown great promise in enabling efficient and stable OPV devices. By investigating the ultrafast charge dynamics using femtosecond laser pulses, the researchers first discovered that controlling the degree of aggregation of the polymerised Y6 acceptors (Y6-PAs) plays a crucial role in promoting electricity generation.

Molecular dynamics (MD) simulations.

The research team further revealed that Y6-PAs exhibit higher miscibility with the donor polymer compared to small molecular acceptors of the same type. This miscibility allows for the formation of a nanoscale percolation network at the heterojunction interface, preventing the aggregation of Y6-PAs. This nanoscale percolation not only enhances charge generation efficiency but also significantly improves the stability of the polymer blend morphology, reducing the loss in device performance over time when exposed to solar illumination.

In response to this breakthrough, Prof Philip C.Y. Chow expressed his enthusiasm, stating: “Our discovery opens up new possibilities for the development of efficient and stable polymer-based solar PV panels, paving the way for more sustainable and viable solar energy solutions that can be seamlessly integrated into our environment, including buildings, vehicles, electronic products and even clothes.”

Near-complete destruction of PFAS in aqueous film-forming foam by integrated photo-electrochemical processes

by Yunqiao Guan, Zekun Liu, Nanyang Yang, Shasha Yang, Luz Estefanny Quispe-Cardenas, Jinyong Liu, Yang Yang in Nature Water

As the U.S. Environmental Protection Agency cracks down on insidious “forever chemical” pollution in the environment, military and commercial aviation officials are seeking ways to clean up such pollution from decades of use of fire suppressant foams at military air bases and commercial airports.

Fire-suppression foams contain hundreds unhealthful forever chemicals, known by chemists as PFAS or poly- and per-fluoroalkyl substances. These compounds have stubbornly strong fluorine-to-carbon bonds, which allow them to persist indefinitely in the environment, hence the moniker “forever chemicals.” Also found many other products, PFAS compounds now contaminate groundwater supplies tapped by municipal water suppliers at many locations throughout the nation.

Because they are linked to higher risks for certain cancers and other maladies, the EPA imposed a new rule last month requiring water utilities to reduce contamination if levels exceeded 4 parts per trillion for certain PFAS compounds.

Fortunately, a collaborative discovery by scientists at UC Riverside and Clarkson University in Potsdam, N.Y., provides a new strategy to clean up these pollutants. The method was detailed. It involves treating heavily contaminated water with ultra-violet (UV) light, sulfite, and a process called electrochemical oxidation, explained UCR associate professor Jinyong Liu.

“In this work, we continued our research on the UV-based treatment, but this time, we had a collaboration with an electrochemical oxidation expert at Clarkson University,” said Liu, who has published nearly 20 papers on treating PFAS pollutants in contaminated water.. “We put these two steps together and we achieved near-complete destruction of PFAS in various water samples contaminated by the foams.”

(Map/Department of Defense)

Liu said the collaboration with a team led by assistant professor Yang Yang at Clarkson solved major technical problems. For instance, the foams contain various other concentrated organic compounds that hinder the breakup of the strong fluorine-to-carbon bonds in the PFAS compounds.

Liu and Yang, however, found that electrochemical oxidation also breaks up these organics. Their process also allows these reactions to occur at room temperature without a need for additional heat or high pressure to stimulate the reaction.

“In the real world, the contaminated water can be very complicated,” Liu said. “It contains a lot of things that might potentially slow down the reaction.”

PFAS compounds have been used in thousands of products ranging from potato chip bags to non-stick cookware, but fire-suppressing foams are a major source of PFAS pollution in groundwater because have been used for for decades to extinguish aviation fuel fires at hundreds of military sites and commercial airports. These foams were also routinely applied to minor fuel spills as a precautionary measure to prevent fires.

Invented by the U.S. Navy in the 1960s, the foams form an aqueous film around burning gasoline and other flammable liquids, which quickly deprives the fire of oxygen and extinguishes it. Because of widespread use, the Department of Defense ordered assessments of 715 military sites nationally for PFAS releases and, by the end of last year, found that 574 of these sites need further investigations or cleanups as required by federal law.

PFAS cleanups became more urgent last month when the EPA imposed a new rule requiring water utilities to reduce contamination if levels exceeded 4 parts per trillion for certain PFAS compounds.

Liu said the method he developed with Yang is well suited for cleansing heavily contaminated water used to flush out tanks, hoses, and other firefighting equipment. The method also can be used to treat leftover containers of PFAS-containing foams.

Their method can also help water utilities deal with groundwater pollution. Contaminated groundwater is often treated through ion exchange technologies in which the PFAS molecules glob onto resin beads in large treatment tanks. The UV light and electrochemical oxidation method developed by Liu and Yang also can assist the regeneration of beads so they can be recycled, Liu said.

“We want to have sustainable management of the resin,” Liu said. “We want to reuse it.”

Atomically dispersed hexavalent iridium oxide from MnO 2 reduction for oxygen evolution catalysis

by Ailong Li, Shuang Kong, Kiyohiro Adachi, Hideshi Ooka, Kazuna Fushimi, Qike Jiang, Hironori Ofuchi, Satoru Hamamoto, Masaki Oura, Kotaro Higashi, Takuma Kaneko, Tomoya Uruga, Naomi Kawamura, Daisuke Hashizume, Ryuhei Nakamura in Science

Researchers report a new method that reduces the amount of iridium needed to produce hydrogen from water by 95%, without altering the rate of hydrogen production. This breakthrough could revolutionize our ability to produce ecologically friendly hydrogen and help usher in a carbon-neutral hydrogen economy.As the world is transitioning from a fossil fuel-based energy economy, many are betting on hydrogen to become the dominant energy currency. But producing “green” hydrogen without using fossil fuels is not yet possible on the scale we need because it requires iridium, a metal that is extremely rare. In a study, researchers led by Ryuhei Nakamura at the RIKEN Center for Sustainable Resource Science (CSRS) in Japan report a new method that reduces the amount of iridium needed for the reaction by 95%, without altering the rate of hydrogen production. This breakthrough could revolutionize our ability to produce ecologically friendly hydrogen and help usher in a carbon-neutral hydrogen economy.

With 70% of the world covered in water, hydrogen is truly a renewable source of energy. However, extracting hydrogen from water on a scale that can rival fossil fuel-based energy production is not yet possible. Current global energy production is almost 18 terawatts, meaning that at any given moment, about 18 trillion watts of power is being produced on average worldwide. For alternative green methods of energy production to replace fossil fuels, they must be able to reach the same rates of energy production.

The green way to extract hydrogen from water is an electrochemical reaction that requires a catalyst. The best catalysts for this reaction — the ones that yield the highest rate and the most stable hydrogen production — are rare metals, with iridium being the best of the best. But the scarcity of iridium is a big problem.

“Iridium is so rare that that scaling up global hydrogen production to the terawatt scale is estimated to require 40 years’ worth of iridium,” says co-first author Shuang Kong.

The Biofunctional Catalyst Research Team at RIKEN CSRS is trying to get around the iridium bottleneck and find other ways of producing hydrogen at high rates for long periods of time. In the long run, they hope to develop new catalysts based on common earth metals, which will be highly sustainable. In fact, the team recently succeeded in stabilizing green hydrogen production at a relatively high level using a form of manganese oxide as a catalyst. However, achieving industrial level production in this manner is still years away.

“We need a way to bridge the gap between rare metal- and common metal-based electrolyzers, so that we can make a gradual transition over many years to completely sustainable green hydrogen,” says Nakamura. The current study does just that by combining manganese with iridium. The researchers found that when they spread out individual iridium atoms on a piece of manganese oxide so that they didn’t touch or clump with each other, hydrogen production in a proton exchange membrane (PEM) electrolyzer was sustained at the same rate as when using iridium alone, but with 95% less iridium.

With the new catalyst, continuous hydrogen production was possible for over 3000 hours (about 4 months) at 82% efficiency without degradation.

“The unexpected interaction between manganese oxide and iridium was key to our success,” says co-author Ailong Li. “This is because the iridium resulting from this interaction was in the rare and highly active +6 oxidation state.”

Nakamura believes that the level of hydrogen production achieved with the new catalyst has high potential for immediate usefulness.

“We expect our catalyst to be easily transferred to real-world applications,” he says, “which will immediately increase the capacity of current PEM electrolyzers.”

The team has begun collaborating with partners in industry, who have already been able to improve on the initial iridium-manganese catalyst. Moving forward, the RIKEN CSRS researchers plan to continue investigating the specific chemical interaction between iridium and manganese oxide, with hopes of reducing the amount of necessary iridium even more. At the same time, they will continue collaborating with industrial partners, and plan on deploying and testing the new catalyst on an industrial scale in the near future.

Impact of global heterogeneity of renewable energy supply on heavy industrial production and green value chains

by Philipp C. Verpoort, Lukas Gast, Anke Hofmann, Falko Ueckerdt in Nature Energy

Countries with limited potential for renewables could save up to 20 percent of costs for green steel and up to 40 percent for green chemicals from green hydrogen if they relocated their energy-intensive production and would import from countries where renewable energy is cheaper, finds a new study by the Potsdam Institute for Climate Impact Research (PIK). This ‘renewables pull’ would create strong incentives for businesses to invest in low-emission production facilities in these renewable-rich countries. Renewable-scarce countries could put all focus on down-stream production and refinement as the smart way to secure industrial competitiveness.

“Our new study shows that renewable-scarce countries like parts of the EU, Japan and South Korea could save between 18 to 38 percent in production costs,” explains Philipp Verpoort, scientist at the Potsdam Institute for Climate Impact Research (PIK) and lead author of the study. “They could do so by relocating their production of industrial basic materials like green steel and chemicals based on green hydrogen to countries where renewable energy is cheap.”

The use of renewable electricity and green hydrogen is a key solution to cut greenhouse-gas emissions when producing steel and chemicals. However, not all industrialized countries would be able to produce these in sufficient quantities and at competitive prices in the long term due to their geographical conditions.

“If these countries focus on producing green hydrogen domestically or importing it, this will be costly for both industry and society. It could even become a dead-end as it results in a lack of long-term competitiveness on global markets. Importing industrial intermediate goods such as iron sponge, ammonia, or methanol and focusing on down-stream production and refinement could be a cheaper and more robust strategy for securing competitiveness,” explains Verpoort.

Emerging green value chains and the associated production steps, feedstock flows and trade options.

To arrive at these results, the scientists looked at the green value chains of three primary basic materials: steel, urea and ethylene. They argue that an electricity-price difference of 4ct/kWh between some existing renewable-scarce industrial production sites (e.g. Germany, Japan or South Korea) and favourable locations elsewhere on the globe (e.g. Australia, Chile, South Africa) can be expected in 2040. The researchers then assessed the cost effectiveness of competing decarbonisation strategies by comparing different trade options — import of industrial products, import of intermediate products, import of hydrogen, and no imports (i.e. full domestic production). Their research demonstrates that cost savings in case of relocation could be huge and that importing hydrogen does not seem to be a cost-effective strategy — especially when imports occur via ship.

The study also discusses other factors that will influence the investment decisions of companies, such as benefits of short and integrated value chains, reliability of supply chains, quality requirements, and public subsidies for low-emission production. However, according to the authors, those alone are unlikely to prevent a partial ‘green relocation’ of production, given the magnitude of cost savings derived in the study.

“We anticipate a global reconfiguration of trade and production in energy-intensive industry sectors. Production will likely shift towards countries abundant in renewable resources while moving away from regions facing constraints in this regard. This shift is often labeled as ‘deindustrialization’ by proponents of costly, permanent industrial policies aimed at protecting national production. However, this term is both inaccurate and misleading,” explains Falko Ueckerdt, Senior Scientist at PIK and co-author of the study. “It is only the first few steps of the long value chains of energy-intensive basic materials that will likely be relocated. This shift presents a potential win-win scenario for both importing and exporting countries. Developing countries with cheap access to renewables, for instance, stand to become exporters and reap the benefits of industrialization. At the same time, industrialized countries can focus on their economic strengths by specializing in those industrial activities that create the most economic value from scarce and expensive green energy, such as making green steel from sponge iron and processing it further.”

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