New Efficient Materials For Solar Fuel Cells

University of Texas at Arlington (UTA) chemists have developed new high-performing materials for cells that harness sunlight to split carbon dioxide and water into useable fuels like methanol and hydrogen gas. These “green fuels” can be used to power cars, home appliances or even to store energy in batteries.

solar fuel cells

Technologies that simultaneously permit us to remove greenhouse gases like carbon dioxide while harnessing and storing the energy of sunlight as fuel are at the forefront of current research,” said Krishnan Rajeshwar, UTA distinguished professor of chemistry and biochemistry and co-founder of the University’s Center of Renewable Energy, Science and Technology. “Our new material could improve the safety, efficiency and cost-effectiveness of solar fuel generation, which is not yet economically viable,” he added.

The new hybrid platform uses ultra-long carbon nanotube networks with a homogeneous coating of copper oxide nanocrystals. It demonstrates both the high electrical conductivity of carbon nanotubes and the photocathode qualities of copper oxide, efficiently converting light into the photocurrents needed for the photoelectrochemical reduction process. Morteza Khaledi, dean of the UTA College of Science, said Rajeshwar’s work is representative of the University’s commitment to addressing critical issues with global environmental impact under the Strategic Plan 2020.

Source: https://www.uta.edu/

Ocean: NanoMotors Remove Ninety Percent Of The Carbon Dioxide

Machines that are much smaller than the width of a human hair could one day help clean up carbon dioxide pollution in the oceans. Nanoengineers at the University of California, San Diego have designed enzyme-functionalized micromotors that rapidly zoom around in water, remove carbon dioxide and convert it into a usable solid form. The proof of concept study represents a promising route to mitigate the buildup of carbon dioxide, a major greenhouse gas in the environment, said researchers.

nanomotorsNanoengineers have invented tiny tube-shaped micromotors that zoom around in water and efficiently remove carbon dioxide. The surfaces of the micromotors are functionalized with the enzyme carbonic anhydrase, which enables the motors to help rapidly convert carbon dioxide to calcium carbonate

We’re excited about the possibility of using these micromotors to combat ocean acidification and global warming,” said Virendra V. Singh, a postdoctoral scientist in Wang’s research group and a co-first author of this study. In their experiments, nanoengineers demonstrated that the micromotors rapidly decarbonated water solutions that were saturated with carbon dioxide. Within five minutes, the micromotors removed 90 percent of the carbon dioxide from a solution of deionized water. The micromotors were just as effective in a sea water solution and removed 88 percent of the carbon dioxide in the same timeframe.

In the future, we could potentially use these micromotors as part of a water treatment system, like a water decarbonation plant,” said Kevin Kaufmann, an undergraduate researcher in Wang’s lab and a co-author of the study.

The team, led by nanoengineering professor Joseph Wang, has published the work this month in the journal Angewandte Chemie.

Source: http://ucsdnews.ucsd.edu/

How To Trap Greenhouse Gases

Emissions from the combustion of fossil fuels like coal, petroleum and natural gas tend to collect within Earth’s atmosphere as “greenhouse gases” that are blamed for escalating global warming.

So researchers around the globe are on a quest for materials capable of capturing and storing greenhouse gases. This shared goal led researchers at Technische Universität Darmstadt in Germany and the Indian Institute of Technology Kanpur to team up to explore the feasibility of vertically aligned carbon nanotubes (VACNTs) to trap and store two greenhouse gases in particular: carbon dioxide (CO2) and sulfur dioxide (SO2). As the team reports in The Journal of Chemical Physics, from AIP Publishing, they discovered that gas adsorption in VACNTs can be influenced by adjusting the morphological parameters of the carbon nanotube thickness, the distance between nanotubes, and their height.

Carbon nanotubes against greenhouse gases
Snapshots of CO2 adsorption in double-walled carbon nanotube arrays (with an inner tube diameter of 2r=3 nanometers and various inter-tube distance at T=303 K and p=1 bar)

 

These parameters are fundamental for ‘tuning’ the hierarchical pore structure of the VACNTs,” explained Mahshid Rahimi and Deepu Babu, the paper’s lead authors and doctoral students in theoretical physical chemistry and inorganic chemistry at the Technische Universität Darmstadt. “This hierarchy effect is a crucial factor for getting high-adsorption capacities as well as mass transport into the nanostructure. Surprisingly, from theory and by experiment, we found that the distance between nanotubes plays a much larger role in gas adsorption than the tube diameter does.

Source: https://www.aip.org/

How To Remove Greenhouse Gas From the Air

Finding a technology to shift carbon dioxide (CO2), the most abundant anthropogenic greenhouse gas, from a climate change problem to a valuable commodity has long been a dream of many scientists and government officials. Now, a team of chemists says they have developed a technology to economically convert atmospheric CO2 directly into highly valued carbon nanofibers for industrial and consumer products.

carbon nanofibers

We have found a way to use atmospheric CO2 to produce high-yield carbon nanofibers,” says Stuart Licht, Ph.D., who leads a research team at George Washington University. “Such nanofibers are used to make strong carbon composites, such as those used in the Boeing Dreamliner, as well as in high-end sports equipment, wind turbine blades and a host of other products.

Previously, the researchers had made fertilizer and cement without emitting CO2, which they reported. Now, the team, which includes postdoctoral fellow Jiawen Ren, Ph.D., and graduate student Jessica Stuart, says their research could shift COfrom a global-warming problem to a feed stock for the manufacture of in-demand carbon nanofibers.

Licht calls his approach “diamonds from the sky.” That refers to carbon being the material that diamonds are made of, and also hints at the high value of the products, such as the carbon nanofibers that can be made from atmospheric carbon and oxygen.

A press conference on this topic will be held Wednesday, Aug. 19, at 9:30 a.m. Eastern time in the Boston Convention & Exhibition Center. Reporters may check-in at Room 153B in person, or watch live on YouTube. To ask questions online, sign in with a Google account.
Source: http://www.acs.org/
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http://home.gwu.edu/

Run A Car With Water And Air

The German automaker Audi announced it has created the first batch of liquid “e-diesel” at a research facility in Dresden. The clear fuel is produced through a “power to liquid” process, masterminded by the German clean tech company and Audi partner Sunfire.

The process uses carbon dioxide, the most common greenhouse gas, which can be captured directly from air. Carbon dioxide is created largely by burning fossil fuels and contributes to global warming. Now Sunfire said it can recycle the gas to make a more efficient, carbon-neutral fuel.
Unlike conventional fossil fuels, the “e-diesel” doesn’t contain sulphur and other contaminants.
audi e-diesel
The engine runs quieter and fewer pollutants are being created,” Sunfire‘s Christian von Olshausen said.
The fuel is produced in three steps. First, the researchers heat up steam to very high temperatures to break it down into hydrogen and oxygen. This process requires temperatures of over 800 degrees Celsius (1,472 Fahrenheit) and is powered by green energy such as solar or wind power.
Second, they mix the hydrogen with carbon dioxide under pressure and at high temperature to create so-called blue crude. Lastly, the blue crude is refined into fuels in a similar way fossil crude oil is refined into gasoline.
Audi (AUDVF) said its lab tests have shown the “e-diesel” can be mixed with fossil fuels or used as a fuel on its own.
At this stage the e-diesel cost 40 % more than the regular gasoline per liter to produce.
Source: http://www.sunfire.de/
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http://money.cnn.com/

Nano Sponges Cut Greenhouse Gases

In the fight against global warming, carbon capture – chemically trapping carbon dioxide before it releases into the atmosphere – is gaining momentum, but standard methods are plagued by toxicity, corrosiveness and inefficiency. Using a bag of chemistry tricks, Cornell materials scientists have invented low-toxicity, highly effective carbon-trapping “sponges” that could lead to increased use of the technology. A research team led by Emmanuel Giannelis, Professor of Engineering, has invented a powder that performs as well or better than industry benchmarks for carbon capture.
The researchers have been working on a better, safer carbon-capture method . Their latest consists of a silica scaffold, the sorbent support, with nanoscale pores for maximum surface area. They dip the scaffold into liquid amine, which soaks into the support like a sponge and partially hardens. The finished product is a stable, dry white powder that captures carbon dioxide even in the presence of moisture.

nanosponges
A scanning electron microscopy image of a pristine silica support, before the amine is added
We have made great strides in sustainability, particularly in the energy supply areas of alternative energy sources, and the demand side areas of energy conservation and building design standards,” KyuJung Whang, Cornell’s vice president for facilities services said.

A paper with their results, co-authored by postdoctoral associates Genggeng Qi and Liling Fu, appeared in Nature Communications.
Source: http://news.cornell.edu/

Graphene soaks up Carbon, Cause of Global Warming

Chemists and engineers at Oregon State University (OSU) have discovered a fascinating new way to take some of the atmospheric carbon dioxide that’s causing the greenhouse effect and use it to make an advanced, high-value material for use in energy storage products.This innovation in nanotechnology won’t soak up enough carbon to solve global warming, researchers say. However, it will provide an environmentally friendly, low-cost way to make nanoporous graphene for use in “supercapacitors” – devices that can store energy and release it rapidly. Such devices are used in everything from heavy industry to consumer electronics.

greenhouse gas2
There are other ways to fabricate nanoporous graphene, but this approach is faster, has little environmental impact and costs less,” said Xiulei (David) Ji, an OSU assistant professor of chemistry in the OSU College of Science and lead author on the study. “The product exhibits high surface area, great conductivity and, most importantly, it has a fairly high density that is comparable to the commercial activated carbons. “And the carbon source is carbon dioxide, which is a sustainable resource, to say the least,” Ji said. “This methodology uses abundant carbon dioxide while making energy storage products of significant value.”

The findings were just published in Nano Energy by scientists from the OSU College of Science, OSU College of Engineering, Argonne National Laboratory, the University of South Florida and the National Energy Technology Laboratory in Albany, Ore. The work was supported by OSU.

Source: http://oregonstate.edu/

How To Turn Algae Into Solar Powered Factories

Genes from the family of bacteria that produce vinegar, Kombucha tea and nata de coco have become stars in a project that would turn algae into solar-powered factories for producing the “wonder materialnanocellulose. Reports on advances in getting those genes to produce fully functional nanocellulose were part of the 245th National Meeting & Exposition of the American Chemical Society (ACS), the world’s largest scientific society.
Nanocellulose
If we can complete the final steps, we will have accomplished one of the most important potential agricultural transformations ever,” said R. Malcolm Brown, Jr., Ph.D. “We will have plants that produce nanocellulose abundantly and inexpensively. It can become the raw material for sustainable production of biofuels and many other products. While producing nanocellulose, the algae will absorb carbon dioxide, the main greenhouse gas linked to global warming.

Most cellulose consists of wood fibers and cell wall remains. Very few living organisms can actually synthesize and secrete cellulose in its native nanostructure form of microfibrils. At this level, nanometer-scale fibrils are very hydrophilic and look like jelly. A nanometer is one-millionth the thickness of a U.S. dime. Nevertheless, cellulose shares the unique properties of other nanometer-sized materials — properties much different from large quantities of the same material. Nanocellulose-based materials can be stronger than steel and stiffer than Kevlar. Great strength, light weight and other advantages has fostered interest in using it in everything from lightweight armor and ballistic glass to wound dressings and scaffolds for growing replacement organs for transplantation.

Source: http://www.eurekalert.org/