Tag Archives: water

Artificial Leaf Could Become A Source Of Perpetual Energy

Rice University researchers have created an efficient, low-cost device that splits water to produce hydrogen fuel. The platform developed by the Brown School of Engineering lab of Rice materials scientist Jun Lou integrates catalytic electrodes and perovskite solar cells that, when triggered by sunlight, produce electricity. The current flows to the catalysts that turn water into hydrogen and oxygen, with a sunlight-to-hydrogen efficiency as high as 6.7%. This sort of catalysis isn’t new, but the lab packaged a perovskite layer and the electrodes into a single module that, when dropped into water and placed in sunlight, produces hydrogen with no further input. The platform introduced by Lou, lead author and Rice postdoctoral fellow Jia Liang and their colleagues in the American Chemical Society journal ACS Nano is a self-sustaining producer of fuel that, they say, should be simple to produce in bulk.

A schematic and electron microscope cross-section show the structure of an integrated, solar-powered catalyst to split water into hydrogen fuel and oxygen. The module developed at Rice University can be immersed into water directly to produce fuel when exposed to sunlight

The concept is broadly similar to an artificial leaf,” Lou said. “What we have is an integrated module that turns sunlight into electricity that drives an electrochemical reaction. It utilizes water and sunlight to get chemical fuels.”

Perovskites are crystals with cubelike lattices that are known to harvest light. The most efficient perovskite solar cells produced so far achieve an efficiency above 25%, but the materials are expensive and tend to be stressed by light, humidity and heat.  “Jia has replaced the more expensive components, like platinum, in perovskite solar cells with alternatives like carbon,” Lou commented. “That lowers the entry barrier for commercial adoption. Integrated devices like this are promising because they create a system that is sustainable. This does not require any external power to keep the module running.”

Liang said the key component may not be the perovskite but the polymer that encapsulates it, protecting the module and allowing to be immersed for long periods. “Others have developed catalytic systems that connect the solar cell outside the water to immersed electrodes with a wire,” he explained. “We simplify the system by encapsulating the perovskite layer with a Surlyn (polymer) film.”

The patterned film allows sunlight to reach the solar cell while protecting it and serves as an insulator between the cells and the electrodes, Liang said. “With a clever system design, you can potentially make a self-sustaining loop,” Lou added. “Even when there’s no sunlight, you can use stored energy in the form of chemical fuel. You can put the hydrogen and oxygen products in separate tanks and incorporate another module like a fuel cell to turn those fuels back into electricity.”

Source: https://news.rice.edu/

On Mars or Earth, biohybrid can turn CO2 into new products

If humans ever hope to colonize Mars, the settlers will need to manufacture on-planet a huge range of organic compounds, from fuels to drugs, that are too expensive to ship from Earth. University of California, Berkeley, and Lawrence Berkeley National Laboratory (Berkeley Lab) chemists have a plan for that.

For the past eight years, the researchers have been working on a hybrid system combining bacteria and nanowires that can capture the energy of sunlight to convert carbon dioxide and water into building blocks for organic molecules. Nanowires are thin silicon wires about one-hundredth the width of a human hair, used as electronic components, and also as sensors and solar cells.

A device to capture carbon dioxide from the air and convert it to useful organic products. On left is the chamber containing the nanowire/bacteria hybrid that reduces CO2 to form acetate. On the right is the chamber where oxygen is produced

On Mars, about 96% of the atmosphere is CO2. Basically, all you need is these silicon semiconductor nanowires to take in the solar energy and pass it on to these bugs to do the chemistry for you,” said project leader Peidong Yang, professor of chemistry and Energy at UC Berkeley. “For a deep space mission, you care about the payload weight, and biological systems have the advantage that they self-reproduce: You don’t need to send a lot. That’s why our biohybrid version is highly attractive.”

The only other requirement, besides sunlight, is water, which on Mars is relatively abundant in the polar ice caps and likely lies frozen underground over most of the planet, said Yang, who is a senior faculty scientist at Berkeley Lab and director of the Kavli Energy Nanoscience Institute.

The biohybrid can also pull carbon dioxide from the air on Earth to make organic compounds and simultaneously address climate change, which is caused by an excess of human-produced CO2 in the atmosphere.

In a new paper published in the journal Joule, the researchers report a milestone in packing these bacteria (Sporomusa ovata) into a “forest of nanowires” to achieve a record efficiency: 3.6% of the incoming solar energy is converted and stored in carbon bonds, in the form of a two-carbon molecule called acetate: essentially acetic acid, or vinegar.

Source: https://news.berkeley.edu/

How To Bring Fresh Water To Remote Communities

Researchers at the University of Bath (UK) have developed a revolutionary desalination process that has the potential to be operated in mobile, solar-powered units. The process is low cost, low energy and low maintenance, and has the potential to provide safe water to communities in remote and disaster-struck areas where fresh water is in short supply.

Developed by the university’s Water Innovation and Research Centre in partnership with Indonesia’s Bogor Agricultural University and the University of Johannesburg, the prototype desalination unit is a 3D-printed system with two internal chambers designed to extract and/or accumulate salt. When power is applied, salt cations (positively charged ions) and salt anions (negatively charged ions) flow between chambers through arrays of micro-holes in a thin synthetic membrane. The flow can only happen in one direction thanks to a mechanism that has parallels in mobile-phone technology. As a result of this one-way flow, salt is pumped out of seawater. This contrasts with the classical desalination process, where water rather than salt is pumped through a membrane.

Desalination, which turns seawater into fresh water, has become an essential process for providing drinking and irrigation water where freshwater is scarce. Traditionally, it has been an energy-intensive process carried out in large industrial plants.

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There are times when it would be enormously beneficial to install small, solar-powered desalination units to service a small number of households. Large industrial water plants are essential to 21st Century living, but they are of no help when you’re living in a remote location where drinking water is scarce, or where there is a coastal catastrophe that wipes out the fresh water supply,” said Professor Frank Marken from the Department of Chemistry

The Bath desalination system is based on ‘ionics’, where a cationic diode (a negatively charged, semi-permeable membrane studded with microscopic pores) is combined with an anionic resistor (a device that only allows the flow of negative ions when power is applied).

This amounts to a whole new process for removing salt from water,”explained Prof Marken. “We are the first people to use tiny micron-sized diodes in a desalination prototype.

He added: “This is a low-energy system with no moving parts. Other systems use enormous pressures to push the water through nano-pores, but we only remove the salts. Most intriguingly, the external pumps and switches can be replaced by microscopic processes inside the membrane – a little bit like biological membranes work.”

Source: https://www.bath.ac.uk/

Little Algae Bioreactor Removes As Much Carbon Dioxide as 4000m2 of Trees

Algae could play a surprising role in the fight against climate change. A.I.-focused technology firm Hypergiant Industries announced a machine that uses the aquatic organisms to sequester carbon dioxide. Algae, the company claims, is “one of nature’s most efficient machines.” By pairing it with a machine learning system, its developers hope to make these talents even more effective. That’s not all. The team claims the device, which measures three feet (90 centimeters) on each side and seven feet (2,1 meters) tall, can sequester as much carbon as a whole acre (4000 square meters) of trees — estimated somewhere around two tons.

We’ve been thinking about climate change solutions in only a very narrow scope,” Ben Lamm, CEO of the Austin-based firm, said. “Trees are part of the solution but there are so many other biological solutions that are useful. Algae is much more effective than trees at reducing carbon in the atmosphere, and can be used to create carbon negative fuels, plastics, textiles, food, fertilizer and much more.”
It’s not the only ambitious idea in the works at the six-division Hypergiant Industries. Its Galactic division is aiming to build a multi-planetary internet by using satellites as relays. Last month, it took the wraps off a prototype Iron Man-like helmet that could aid search and rescue teams. The company, founded last year, counts Bill Nye and astronaut Andy Allen among its advisory board members.

Hypergiant’s algae-powered bioreactor is the sort of idea that could be needed now more than ever. Despite a push to greener technologies, global annual carbon emissions rose in 2018 to hit an all-time high of 37.1 billion tonnes. That’s after two years of a relative plateau between 2014 and 2016. This has resulted in a global climate shift, where 2018 was the fourth-hottest year on record. Several countries, including the United Kingdom, have pledged to reach net-zero emissions by 2050.

Research has shown that restoring forests by an area the size of the United States could cut carbon dioxide in the atmosphere by a staggering 25 percent, reaching levels not seen for a century. While planting trees could play an important role in the pushback, alternative solutions like carbon capture and storage and new sequestering technologies could also help remove carbon from the atmosphere.

Algae, Hypergiant Industries explains, needs three elements for growth: light, water, and carbon dioxide. The machine monitors factors like light, available carbon dioxide, temperature and more to maximize the amount sequestered by the algae.

One Eos Bioreactor sequesters the same amount of carbon from the atmosphere as an entire acre of trees,” Lamm says. “With enough Eos devices, we could make whole cities carbon-neutral or even negative, and at a rate that is so much faster than that of trees. That’s the dream: breathable, livable cities for everyone and right now.”

When the algae consumes carbon dioxide, it produces biomass. The company has suggested that this biomass could be used in a number of applications, like making oils or cosmetics. A smart city could take the biomass and use it for fuels. The machine is small enough to fit inside office buildings, and Lamm tells FastCompany that the initial prototype it’s currently operating can attach to a building’s HVAC system to clean the air inside.

Solar-driven Water Splitting Catalyst Produces Hydrogen

Engineers from Lehigh University (Bethlehem, Pennsylvania)  are the first to utilize a single enzyme biomineralization process to create a catalyst that uses the energy of captured sunlight to split water molecules to produce hydrogen. The synthesis process is performed at room temperature and under ambient pressure, overcoming the sustainability and scalability challenges of previously reported methods.

Solar-driven water splitting is a promising route towards a renewable energy-based economy. The generated hydrogen could serve as both a transportation fuel and a critical chemical feedstock for fertilizer and chemical production. Both of these sectors currently contribute a large fraction of total greenhouse gas emissions.

One of the challenges to realizing the promise of solar-driven energy production is that, while the required water is an abundant resource, previously-explored methods utilize complex routes that require environmentally-damaging solvents and massive amounts of energy to produce at large scale. The expense and harm to the environment have made these methods unworkable as a long-term solution.

Now a team of engineers at Lehigh have harnessed a biomineralization approach to synthesizing both quantum confined nanoparticle metal sulfide particles and the supporting reduced graphene oxide material to create a photocatalyst that splits water to form hydrogen. The team reported their results in an article entitled: “Enzymatic synthesis of supported CdS quantum dot/reduced graphene oxide photocatalysts” featured on the cover of the August 7 issue of Green Chemistry, a journal of the Royal Society of Chemistry. “Our water-based process represents a scalable green route for the production of this promising photocatalyst technology,” says Professor Steven McIntosh, who is also associate director of Lehigh’s Institute for Functional Materials and Devices.

Source: https://engineering.lehigh.edu/

Ruthenium-based Catalyst Outperforms Platinum To Produce Hydrogen

A novel ruthenium-based catalyst developed at UC Santa Cruz has shown markedly better performance than commercial platinum catalysts in alkaline water electrolysis for hydrogen production. The catalyst is a nanostructured composite material composed of carbon nanowires with ruthenium atoms bonded to nitrogen and carbon to form active sites within the carbon matrix.

The electrochemical splitting of water to produce hydrogen is a crucial step in the development of hydrogen as a clean, environmentally friendly fuel (for car or heating system). Much of the effort to reduce the cost and increase the efficiency of this process has focused on finding alternatives to expensive platinum-based catalysts. At UC Santa Cruz, researchers led by Shaowei Chen, professor of chemistry and biochemistry, have been investigating catalysts made by incorporating ruthenium and nitrogen into carbon-based nanocomposite materials. Their new findings, published February 7 in Nature Communications, not only demonstrate the impressive performance of their ruthenium-based catalyst but also provide insights into the mechanisms involved, which may lead to further improvements.

Electron microscopy of carbon nanowires co-doped with ruthenium and nitrogen shows ruthenium nanoparticles decorating the surface of the nanowires. Elemental mapping analysis shows individual ruthenium atoms within the carbon matrix (red arrows, below).

 

 

 

 

 

 

 

 

This is a clear demonstration that ruthenium can have remarkable activity in catalyzing the production of hydrogen from water,” Chen said. “We also characterized the material on the atomic scale, which helped us understand the mechanisms, and we can use these results for the rational design and engineering of ruthenium-based catalysts.

Electron microscopy and elemental mapping analysis of the material showed ruthenium nanoparticles as well as individual ruthenium atoms within the carbon matrix. Surprisingly, the researchers found that the main sites of catalytic activity were single ruthenium atoms rather than ruthenium nanoparticles.

Source: https://news.ucsc.edu/

A Super Protein Brings The Equivalence Of Meat For Vegeterian Diet

Protein is what’s for dinner, but only if the world’s biggest food companies can keep up. The rise in global appetites for everything from meat to beans and peas is creating what experts call a “perfect storm” for environmental concern, as farmers must increasingly crank out more food with less land and water.

A new startup has one possible solution. called Sustainable Bioproducts, the company sources protein from ingredients found deep inside an unlikely source: the searing volcanic hot springs in Yellowstone National Park. To make the product, the company brews it up using a process similar to that used to make beer.

What comes out, explained CEO Thomas Jonas , is a neutral-tasting, naturally high-protein substance that can either be mixed into yogurt for an alternative to the Greek variety or shaped into patties for the next plant-based burger. Plus, the startup’s product is naturally rich in some of the same key amino acids that the body needs to function. Often found in animal products like eggs, these protein building blocks are especially tough to procure from a vegan or vegetarian diet.

What we have here is a super protein,” Jonas said. “And it comes from one of the most pristine wild places on the planet.”

On Monday, the startup launched publicly with $33 million in funds from Silicon Valley-based venture firm 1955 Capital and the venture arms of two leading global food suppliersgrain company Archer Daniels Midland and multinational food producer Danone. Based in Chicago, the startup is using the funds to build a production plant and cook up several prototype products.

Key to the startup’s operation, Jonas said, is that it will require a fraction of the natural resources needed for making other proteins like meat and nuts. In place of wasteful factory farms or large parcels of land, all they need, according to Jonas, is essentially a series of brewer’s vats. The company’s core technology is the process it uses to ferment a set of unique microorganisms first discovered in Yellowstone by Montana State University scientist Mark Kozubal nearly a decade ago. Now serving as the startup’s chief science officer, Kozubal came across the organisms as part of a research project supported by grants from the Environmental Protection Agency, the National Science Foundation, and NASA. Sustainable Bioproducts also independently received grants from all three organizations.

Source: https://www.sustainablebioproducts.com/
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Jell-O To Make Powerful New Hydrogen Fuel Catalyst

A cheap and effective new catalyst developed by researchers at the University of California, Berkeley, can generate hydrogen fuel from water just as efficiently as platinum, currently the best — but also most expensivewater-splitting catalyst out there.

The catalyst, which is composed of nanometer-thin sheets of metal carbide, is manufactured using a self-assembly process that relies on a surprising ingredient: gelatin, the material that gives Jell-O its jiggle.

Two-dimensional metal carbides spark a reaction that splits water into oxygen and valuable hydrogen gas. Berkeley researchers have discovered an easy new recipe for cooking up these nanometer-thin sheets that is nearly as simple as making Jell-O from a box

Platinum is expensive, so it would be desirable to find other alternative materials to replace it,” said senior author Liwei Lin, professor of mechanical engineering at UC Berkeley. “We are actually using something similar to the Jell-O that you can eat as the foundation, and mixing it with some of the abundant earth elements to create an inexpensive new material for important catalytic reactions.

The work appears in the print edition of the journal Advanced Materials.

Source: https://news.berkeley.edu/

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How To Make Toxic Water Safe And Drinkable

In Australia, UNSW and RMIT researchers have discovered a revolutionary and cheap way to make filters that can turn water contaminated with heavy metals into safe drinking water in a matter of minutes. Recent UNSW SHARP hire Professor Kourosh Kalantar-zadeh and his former colleagues at RMIT showed that nano-filters made of aluminium oxide could be cheaply produced using virtually no energy from a fixed amount of liquid metal gallium.

In a paper published in Advanced Functional Materials, lead author Dr Ali Zavabeti (RMIT) and Professor Kalantar-zadeh explained that when a chunk of aluminium is added to the core of liquid gallium at room temperature, layers of aluminium oxide are quickly produced at the surface of the gallium. The authors discovered that these aluminium oxide nano-sheets were highly porous and went on to prove they were suitable for filtering both heavy metal ions and oil contamination at unprecedented, ultra-fast rates. Professor Kalantar-zadeh, who was recently awarded an ARC Australian Laureate Fellowship soon after joining UNSW‘s School of Chemical Engineering, said that low cost and portable filters produced by this new liquid metal based manufacturing process could be used by people without access to clean drinking water to remove substances like lead and other toxic metals in a matter of minutes.

Because it’s super porous, water passes through very rapidly,” Professor Kalantar-zadeh said. “Lead and other heavy metals have a very high affinity to aluminium oxide. As the water passes through billions of layers, each one of these lead ions get attracted to one of these aluminium oxide sheets. “But at the same time, it’s very safe because with repeated use, the water flow cannot detach the heavy metal ions from the aluminium oxide.”

Professor Kalantar-zadeh believes the technology could be put to good use in Africa and Asia in places where heavy metal ions in the water are at levels well beyond safe human consumption. It is estimated that 790 million people, or one in 10 of the Earth’s population, do not have access to clean water. “If you’ve got bad quality water, you just take a gadget with one of these filters with you,” he said. “You pour the contaminated water in the top of a flask with the aluminium oxide filter. Wait two minutes and the water that passes through the filter is now very clean water, completely drinkable. “And the good thing is, this filter is cheap.”

There are portable filtration products available that do remove heavy metals from water, but they are comparatively expensive, often costing more than $100. By contrast, aluminium oxide filters produced from liquid gallium could be produced for as little as 10 cents, making them attractive to prospective manufacturers.

Source: http://newsroom.unsw.edu.au/

Portable Machine Harvests Water From Air

Driven by the scarcity of supply, climate change and ground watershed depletion, scientists present a design for a first of its kind portable harvester that mines freshwater from the atmosphere. For thousands of years, people in the Middle East and South America have extracted water from the air to help sustain their populations. Researchers and students from the University of Akron drew inspiration from those examples to develop a lightweight, battery-powered freshwater harvester that could someday take as much as 10 gallons (37,8 liters) per hour from the air, even in arid locations.

I was visiting China, which has a freshwater scarcity problem. There’s investment in wastewater treatment, but I thought that effort alone was inadequate,University of Akron professor Shing-Chung (Josh) Wong said.

Instead of relying on treated wastewater, Wong explained, it might be more prudent to develop a new type of water harvester that takes advantage of abundant water particles in the atmosphere. Freshwater makes up less than 3 percent of the earth’s water sources, and three quarters of that is locked up as ice in the north and south poles. Most water sustainability research is directed toward water supply, purification, wastewater treatment and desalination. Little attention has been paid to water harvesting from atmospheric particles.

Harvesting water from the air has a long history. Thousands of years ago, the Incas of the Andean region collected dew and channeled it into cisterns. More recently, some research groups have been developing massive mist and fog catchers in the Andean mountains and in Africa. Wong’s harvester is directed towards the most abundant atmospheric water sources and uses ground-breaking nanotechnology. If successful, it will produce an agile, lightweight, portable, freshwater harvester powered by a lithium-ion battery.

By experimenting with different combinations of polymers that were hydrophilic — which attracts water — and hydrophobic — which discharges water, the team concluded that a water harvesting system could indeed be fabricated using nanofiber technology. Unlike existing methods, Wong’s harvester could work in arid desert environments because of the membrane’s high surface-area-to-volume ratio. It also would have a minimal energy requirement. “We could confidently say that, with recent advances in lithium-ion batteries, we could eventually develop a smaller, backpack-sized device,” Wong said.

Source: https://www.uakron.edu/