Solution to plastic pollution on the horizon

Engineering a unique plastic-degrading enzyme

The inner workings of a recently discovered bacterium with a fascinating ability to use plastic as an energy source have been recently revealed in PNAS. The world’s unique Long-Wavelength Macromolecular Crystallography (MX) beamline here at Diamond Light Source was used to successfully solve the structure of the bacterial enzyme responsible for chopping up the plastic. This newly evolved enzyme could be the key to tackling the worldwide problem of plastic waste.

Plastic pollution is a global threat that desperately needs addressing. Plastics are rarely biodegradable and they can remain in the environment for centuries. One of the most abundant plastics that contributes hugely to this dire situation is poly(ethylene terephthalate) (PET).

PET is used largely in textiles, where it is commonly referred to as polyester, but it is also used as packaging for liquids and foodstuffs. In fact, PET’s excellent water-repellent properties led to it being the plastic of choice for soft drink bottles. However, once plastic bottles are discarded in the environment the water resistance of PET means that they are highly resistant to natural biodegradation. PET bottles can linger for hundreds of years and plastic waste like this will accumulate over time unless a solution is found to degrade them.

A recent breakthrough came in the discovery of a unique bacterium, Ideonella sakaiensis 201-F6, which was found feeding on waste from an industrial PET recycling facility. PET has only been widely used since the 1970s, so the bacterium had evolved at breakneck speed to be able to take advantage of the new food source.

The bacterium had the amazing ability to degrade PET and use it to provide carbon for energy. Central to this ability was the production of a PET-digesting enzyme, known as PETase.

>Read more on the Diamond Light Source website


Climate change and its effects on Rocky Mountain alpine lakes

Alpine lakes in the Rocky Mountains are important biological hot spots of that ecosystem. These lakes do not have enough nutrients to support large amounts of aquatic life because of the cold climate in the surrounding watershed. Rather, the lakes are home to oligotrophs, organisms that grow slowly and can survive in harsh aquatic environments. The lakes also host a variety of cold-water fish, such as trout, that are preyed upon by birds, including osprey and bald eagles.

Researchers from University of Wyoming, U.S. Geological Survey, and the Canadian Light Source conducted experiments at the CLS on the fine dust that is deposited to the Rocky Mountains to learn more about how the alpine lakes could be affected by climate change. They looked specifically at phosphorus in dust and how it is made available to the organisms in the cold lakes and streams, because phosphorus is one of the major limiting nutrients, and its availability could affect the functions and properties of alpine lake ecosystems.

>Read more on the Canadian Light Source website


Converting CO2 into usable energy

Scientists show that single nickel atoms are an efficient, cost-effective catalyst for converting carbon dioxide into useful chemicals.

Imagine if carbon dioxide (CO2) could easily be converted into usable energy. Every time you breathe or drive a motor vehicle, you would produce a key ingredient for generating fuels. Like photosynthesis in plants, we could turn CO2 into molecules that are essential for day-to-day life. Now, scientists are one step closer.

Researchers at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory are part of a scientific collaboration that has identified a new electrocatalyst that efficiently converts CO2 to carbon monoxide (CO), a highly energetic molecule. Their findings were published on Feb. 1 in Energy & Environmental Science.

“There are many ways to use CO,” said Eli Stavitski, a scientist at Brookhaven and an author on the paper. “You can react it with water to produce energy-rich hydrogen gas, or with hydrogen to produce useful chemicals, such as hydrocarbons or alcohols. If there were a sustainable, cost-efficient route to transform CO2 to CO, it would benefit society greatly.”

>Read more on the NSLS-II website

Image: Brookhaven scientists are pictured at NSLS-II beamline 8-ID, where they used ultra-bright x-ray light to “see” the chemical complexity of a new catalytic material. Pictured from left to right are Klaus Attenkofer, Dong Su, Sooyeon Hwang, and Eli Stavitski.


Unraveling the Complexities of Auto-Oxidation

Study reveals mechanism in spruce tree that causes growth

While it’s common knowledge that trees grow when days start to become longer in the springtime and stop growing when days become shorter in the fall, exactly how this happens has not been well understood.

Now, scientists using the Canadian Light Source are offering insights into the mechanisms of how certain cells in the winter buds of Norway spruce respond to changes in seasonal light, affecting growth. The research was published in Frontiers in Plant Science.

Such knowledge allows for better predictions of how trees might respond to climate change, which could bring freezing temperatures while daylight is still long or warmer temperatures when daylight is short.

Professor Jorunn E. Olsen and YeonKyeong Lee, plant scientists at the Norwegian University of Life Sciences, along with colleagues from the University of Saskatchewan investigated winter bud cells from Norway spruce and how they differ with respect to the amount of daylight to which they were exposed.

>Read more on the Candian Light Source website

Image (from left to right, extract): plant with terminal winter bud after short day exposure for three weeks; plant with brown bud scales after short day exposure for eight weeks; plant showing bud break and new growth three weeks after re-transfer to long days following eight weeks under short days. Entire picture here.

Atomic Flaws Create Surprising, High-Efficiency UV LED Materials

Subtle surface defects increase UV light emission in greener, more cost-effective LED and catalyst materials

Light-emitting diodes (LEDs) traditionally demand atomic perfection to optimize efficiency. On the nanoscale, where structures span just billionths of a meter, defects should be avoided at all costs—until now.

A team of scientists from the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory and Stony Brook University has discovered that subtle imperfections can dramatically increase the efficiency and ultraviolet (UV) light output of certain LED materials.

“The results are surprising and completely counterintuitive,” said Brookhaven Lab scientist Mingzhao Liu, the senior author on the study. “These almost imperceptible flaws, which turned out to be missing oxygen in the surface of zinc oxide nanowires, actually enhance performance. This revelation may inspire new nanomaterial designs far beyond LEDs that would otherwise have been reflexively dismissed.”

>Read more on the NSLS-II website

Image: The research team, front to back and left to right: Danhua Yan, Mingzhao Liu, Klaus Attenkoffer, Jiajie Cen, Dario Stacciola, Wenrui Zhang, Jerzy Sadowski, Eli Stavitski.


The power of Metal-Organic Frameworks

Trapping nuclear waste at the molecular level

Nuclear power currently supplies just over 10% of the world’s electricity. However one factor hindering its wider implementation is the confinement of dangerous substances produced during the nuclear waste disposal process. One such bi-product of the disposal process is airborne radioactive iodine that, if ingested, poses a significant health risk to humans.  The need for a high capacity, stable iodine store that has a minimised system volume is apparent – and this collaborative research project may have found a solution.

Researchers have successfully used ultra-stable MOFs to confine large amounts of iodine to an exceptionally dense area. A number of complementary experimental techniques, including measurements taken at Diamond Light Source and ISIS Neutron and Muon Source, were coupled with theoretical modelling to understand the interaction of iodine within the MOF pores at the molecular level.

High resolution x-ray powder diffraction (PXRD) data were collected at Diamond’s I11 beamline. The stability and evolution of the MOF pore was monitored as the iodine was loaded into the structure. Comparison of the loaded and empty samples revealed the framework not only adsorbed but retained the iodine within its structure.

>Read more on the Diamond Light Source website

Illustration: Airborne radioactive iodine is one of the bi-products of the nuclear waste disposal process. A recent study involving Diamond Light Source and ISIS Neutron and Muon Source showed how MOFs can capture and store iodine which may have implications for the future confinement of these hazardous substances.

Scientists develop process to produce higher quality fuel from biowaste

Researchers have found a way to produce a higher quality, more stable fuel from biowaste, such as sewage, that is simpler and cleaner than existing methods.

“This puts biofuel closer to being a good substitute for fossil fuels,” said Hua Song (picture), an associate professor of chemical and petroleum engineering at the University of Calgary. Song and his research team recently published the results of their research conducted at the Canadian Light Source in the journal Fuel.
“The world energy market is currently dominated by fossil fuels. With increasing concern surrounding climate change and dwindling resources that are associated with the use of fossil fuels, renewable energy sources are becoming increasingly desirable and are currently the fast growing energy source,” wrote Song in the research paper.

>Read more on the Canadian Light Source website


From greenhouse gases to plastics

New catalyst for recycling carbon dioxide discovered

Imagine if we could take CO2, that most notorious of greenhouse gases, and convert it into something useful. Something like plastic, for example. The positive effects could be dramatic, both diverting CO2 from the atmosphere and reducing the need for fossil fuels to make products.

A group of researchers, led by the University of Toronto Ted Sargent group, just published results that bring this possibility a lot closer.

Using the Canadian Light Source and a new technique exclusive to the facility, they were able to pinpoint the conditions that convert CO2 to ethylene most efficiently. Ethylene, in turn, is used to make polyethylene—the most common plastic used today—whose annual global production is around 80 million tonnes.


>Read more on the Canadian Light Source website


Approved! The EU INFINITE-CELL project

A large EU-sponsored research project on tandem solar cells in which HZB is participating begins in November 2017.

The goal is to combine thin-film semiconductors made of silicon and kesterites into especially cost-effective tandem cells having efficiencies of over 20 per cent. Several large research institutions from Europe, Morocco, the Republic of South Africa, and Belarus will be working on the project, as well as two partners from industry.

“We not only have detailed experience with kesterite thin films, but also a wide spectrum of analytical methods at our disposal to characterise absorber materials very thoroughly”, explains Prof. Susan Schorr. The FUNDACIO INSTITUT DE RECERCA DE L’ENERGIA DE CATALUNYA (IREC), Spain – a long-term collaborating partner of the HZB, is coordinating the entire project. The project begins with a kick-off workshop in Brussels in November 2017.

Atmosphere in X-ray light

Light from the particle accelerator helps to understand ozone decomposition

A new experimental chamber coupled to the Swiss Light Source (SLS), a large-scale research facility of the Paul Scherrer Institute PSI, allows researchers to recreate atmospheric processes in the laboratory through unprecedented precision analysis involving X-rays.

In their first experiments, researchers detailed how bromine molecules are formed in the air. These play an essential role in the decomposition of ozone in the lower layers of the atmosphere. With their results, the researchers have also made an important contribution to models designed to explain and predict changes in climate and air composition. In the future, the experimental setup will be available to researchers in all scientific fields and those particularly concerned with the chemistry of the atmosphere or other topics in energy and environmental research.

>Read More on the PSI website

Image: In the experimental chamber, a very thin vertical jet of water can be seen, which flows downward in the middle of the picture from a small tube. During the experiment, the chamber contains a gas mixture including ozone, which reacts on the surface with bromide in the water and produces bromine. As an intermediate step in the process, a short-lived compound of bromide and ozone is made, which was detected for the first time ever with the help of X-ray light from SLS. For this proof, the X-ray light knocked electrons out of the compound, and these made their way to the detector through an opening in the cone (to the left in this photo). (Photo: Paul Scherrer Institute/Mahir Dzambegovic)

Researchers develop technique to reuse carbon dioxide and methane, slowing climate change

Reusing carbon dioxide (CO2) and methane waste emissions from industrial sources is closer to reality.

And this  thanks to recent findings from a project conducted at the Canadian Light Source and the University of Saskatchewan. CO2 and methane are the most significant greenhouse gases resulting from human activity, says Dr. Hui Wang, professor in the Department of Chemical and Biological Engineering at the University of Saskatchewan.

Capturing CO2 and methane emissions from industrial sources and reusing them could reduce the threat on the world’s ecosystem by slowing climate change, says Dr. Wang, the principal researcher of a paper published in Catalyst Today.

CO2 and methane can be triggered to undergo chemical reactions with each other to create synthesis gas or syngas. Syngas is a mixture of carbon monoxide and hydrogen, which can be used to synthesize a variety of liquid fuels or ammonia.

This reaction between CO2 and methane, also called ‘dry reforming of methane’, has not been fully scaled-up for commercial use due to lack of an inexpensive and industrially viable catalyst. Catalysts are used to speed up chemical reactions.

Solar hydrogen production by artificial leafs

Scientists analysed how a special treatment improves cheap metal oxide photoelectrodes

Metal oxides are promising candidates for cheap and stable photoelectrodes for solar water splitting, producing hydrogen with sunlight. Unfortunately, metal oxides are not highly efficient in this job. A known remedy is a treatment with heat and hydrogen. An international collaboration has now discovered why this treatment works so well, paving the way to more efficient and cheap devices for solar hydrogen production.

The fossil fuel age is bound to end, for several strong reasons. As an alternative to fossil fuels, hydrogen seems very attractive. The gas has a huge energy density, it can be stored or processed further, e. g. to methane, or directly provide clean electricity via a fuel cell. If it is produced using sunlight alone, hydrogen is completely renewable with zero carbon emissions.

>Read More

Direct and Efficient Utilization of Solid-phase Iron by Diatoms

A research team indicates that diatoms, can directly uptake iron from insoluble iron sediments, and thereby potentially affect atmospheric carbon dioxide level.

A research team from Columbia University indicates that diatoms, photosynthetic marine organisms responsible for as much as 20% of photosynthesis in the world’s oceans, can directly uptake iron from insoluble iron sediments, and thereby potentially affect atmospheric carbon dioxide level. Although iron is often present in the ocean, usually there is insufficient iron for diatoms and other organisms to grow quickly unless this iron is dissolved and in a form that can be used readily. This research establishes that iron from mineral phases can be quite bioavailable, and that the diatoms can use most forms of iron, but appear to have a preference for a specific form of iron, ferrous iron, in the mineral phases. This research is applicable to a wide variety of questions in earth and ocean sciences, including basic biology of nutrient acquisition, the coupling of physical and geological processes such as glaciers to climate and geoengineering.

>Read More

Picture: Glacial striations seen near Upsala Glacier, Argentina, where scientists collected glacial samples. This physical scraping produces sediments and dust that can fertilize plankton when it is delivered to the ocean.
Photo by Michael Kaplan/Lamont-Doherty Earth Observatory