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Category: chemistry – Page 310

German scientists are researching a method to produce hydrogen using light and photoactive compounds on an organic chemical basis.

Hydrogen is considered to be one of the alternative energy sources of the future. So far, however, the costly and energy-intensive production process has been a major problem with regard to the environmental friendliness of this substance, which is in itself CO2 neutral. For this reason, increasing numbers of scientists around the world are researching other methods of producing hydrogen: from algae, for example. (IO reported). Scientists in Germany at the Friedrich Schiller University, the Leibniz Institute for Photonic Technologies (Leibniz IPHT) and the University of Ulm have taken inspiration from nature for their method of producing hydrogen.

To do so, the team from the “CataLight” Collaborative Research Center at the Universities of Jena and Ulm has combined new organic dyes with non-precious metal catalyst molecules that release gaseous hydrogen in water when irradiated with light. This substitute has shown a remarkable impact in terms of longevity and effect after excitation by visible light, they write in their study, published in Chemistry – A European Journal.

Photosynthesis as inspiration

In nature, sunlight is most effectively stored in chemical bonds through photosynthesis, because the light-collecting and reactive complexes in the thylakoid membrane are fixed in chloroplasts. The researchers led by Prof. Felix Schacher have achieved this type of arrangement with the help of polymers that interact with both hydrophilic and hydrophobic substances. These charged, so-called graft copolymers are produced artificially.

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Scientists at Lehigh University are developing a tiny generating plant, housed on a silicon chip, that they believe can produce enough hydrogen to run power-consuming portable devices.

The amount of hydrogen produced was small, but it was enough to demonstrate that the Lehigh project is feasible. Given time the Lehigh group believes they will develop a working generating plant, housed on a silicon chip that produces sufficient quantities of hydrogen to run different types of power consuming portable devices.

‘About 10 years ago people starting thinking: ‘can we take the same fabrication methods for silicon chips and instead of using them for electronics, use them for something else? said Mayuresh Kothare, assistant professor of chemical engineering.

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A team of researchers affiliated with several institutions in the U.K. and one in Saudi Arabia has developed a way to produce jet fuel using carbon dioxide as a main ingredient. In their paper published in the journal Nature Communications, the group describes their process and its efficiency.

As scientists continue to look for ways to reduce the amount of emitted into the atmosphere, they have increasingly focused on certain business sectors. One of those sectors is the , which accounts for approximately 12% of transportation-related carbon dioxide emissions. Curbing in the aviation industry has proved to be challenging due to the difficulty of fitting heavy batteries inside of aircraft. In this new effort, the researchers have developed a that can be used to produce carbon-neutral jet fuel.

The researchers used a process called the organic combustion method to convert carbon dioxide in the air into jet fuel and other products. It involved using an iron catalyst (with added potassium and manganese) along with hydrogen, citric acid and carbon dioxide heated to 350 degrees C. The process forced the apart from the oxygen atoms in CO2 molecules, which then bonded with hydrogen atoms, producing the kind of hydrocarbon molecules that comprise liquid jet fuel. The process also resulted in the creation of water molecules and other products.

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Scientists in Australia have developed a process for calculating the perfect size and density of quantum dots needed to achieve record efficiency in solar panels.

Quantum dots, man-made nanocrystals 100, 000 times thinner than a sheet of paper, can be used as sensitisers, absorbing infrared and and transferring it to other molecules.

This could enable new types of to capture more of the light spectrum and generate more electrical current, through a process of ‘light fusion’ known as photochemical upconversion.

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Researchers from Tokyo Metropolitan University have discovered a way to make self-assembled nanowires of transition metal chalcogenides at scale using chemical vapor deposition. By changing the substrate where the wires form, they can tune how these wires are arranged, from aligned configurations of atomically thin sheets to random networks of bundles. This paves the way to industrial deployment in next-gen industrial electronics, including energy harvesting, and transparent, efficient, even flexible devices.

Electronics is all about making things smaller—smaller features on a chip, for example, means more computing power in the same amount of space and better efficiency, essential to feeding the increasingly heavy demands of a modern IT infrastructure powered by machine learning and artificial intelligence. And as devices get smaller, the same demands are made of the intricate wiring that ties everything together. The ultimate goal would be a wire that is only an atom or two in thickness. Such would begin to leverage completely different physics as the electrons that travel through them behave more and more as if they live in a one-dimensional world, not a 3D one.

In fact, scientists already have materials like carbon nanotubes and transition metal chalcogenides (TMCs), mixtures of transition metals and group 16 elements which can self-assemble into atomic-scale nanowires. The trouble is making them long enough, and at scale. A way to mass produce nanowires would be a game changer.

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Summary: Artificial intelligence technology redesigned a bacterial protein that helps researchers track serotonin in the brain in real-time.

Source: NIH

Serotonin is a neurochemical that plays a critical role in the way the brain controls our thoughts and feelings. For example, many antidepressants are designed to alter serotonin signals sent between neurons.

In an article in Cell, National Institutes of Health-funded researchers described how they used advanced genetic engineering techniques to transform a bacterial protein into a new research tool that may help monitor serotonin transmission with greater fidelity than current methods. Preclinical experiments, primarily in mice, showed that the sensor could detect subtle, real-time changes in brain serotonin levels during sleep, fear, and social interactions, as well as test the effectiveness of new psychoactive drugs.

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“Once they are ingested, up to 90% of the plastic fragments that reach the intestine are excreted. However, one part is fragmented into nanoplastics which are capable, due to their small size and molecular properties, to penetrate the cells and cause harmful effects. The study establishes that alterations in food absorption have been described, as well as inflammatory reactions in the intestinal walls, changes in the composition and functioning of the gut microbiome, effects on the body’s metabolism and ability to produce, and lastly, alterations in immune responses. The article alerts about the possibility of a long-term exposure to plastic, accumulated throughout generations, could give way to unpredictable changes even in the very genome, as has been observed in some animal models.”

We live in a world invaded by plastic. Its role as a chemically stable, versatile and multi-purpose fostered its massive use, which has finally translated into our current situation of planetary pollution. Moreover, when plastic degrades it breaks into smaller micro and nanoparticles, becoming present in the water we drink, the air we breathe and almost everything we touch. That is how nanoplastics penetrate the organism and produce side effects.

A revised study led by the Universitat Autónoma de Barcelona (UAB), the CREAF and the Centre for Environmental and Marine Studies (CESAM) at the University of Aviero, Portugal, and published in the journal Science Bulletin, verifies that the nanoplastics affect the composition and diversity of our intestinal microbiome and that this can cause damage to our health. This effect can be seen in both vertebrates and invertebrates, and has been proved in situations in which the exposure is widespread and prolonged. Additionally, with alteration of the gut microbiome come alterations in the immune, endocrine and and therefore, although not enough is known about the specific physiological mechanisms, the study alerts that stress to the gut microbiome could alter the health of humans.

The health effects of being exposed to nanoplastics was traditionally evaluated in aquatic animals such as molluscs, crustaceans and fish. Recent in vitro analyzes, using cell cultures of fish and mammals, has allowed scientists to analyze the changes in gene expression associated with the presence of nanoplastics from a toxicological viewpoint. The majority of neurological, endocrine and immunological tracts in these vertebrates are very similar to those of humans, and therefore authors warn that some of the effects observed in these models could also be applied to humans. Understanding and analyzing the process through which these plastic fragments penetrate the organism and harm it is fundamental, as is determining precisely the amount and typology of nanoplastics polluting the environment.

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When it comes to the semiconductor industry, silicon has reigned as king in the electronics field, but it is coming to the end of its physical limits.

To more effectively power the , locomotives and even , Lawrence Livermore National Laboratory (LLNL) scientists are turning to diamond as an ultra-wide bandgap semiconductor.

Diamond has been shown to have superior carrier mobility, break down electric field and thermal conductivity, the most important properties to power . It became especially desirable after the development of a chemical vapor deposition (CVD) process for growth of high-quality single crystals.

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A team of scientists at Freie Universität Berlin has developed an artificial intelligence (AI) method for calculating the ground state of the Schrödinger equation in quantum chemistry. The goal of quantum chemistry is to predict chemical and physical properties of molecules based solely on the arrangement of their atoms in space, avoiding the need for resource-intensive and time-consuming laboratory experiments. In principle, this can be achieved by solving the Schrödinger equation, but in practice this is extremely difficult.

Up to now, it has been impossible to find an exact solution for arbitrary molecules that can be efficiently computed. But the team at Freie Universität has developed a deep learning method that can achieve an unprecedented combination of accuracy and computational efficiency. AI has transformed many technological and scientific areas, from computer vision to materials science. “We believe that our approach may significantly impact the future of quantum ,” says Professor Frank Noé, who led the team effort. The results were published in the reputed journal Nature Chemistry.

Central to both quantum chemistry and the Schrödinger equation is the —a mathematical object that completely specifies the behavior of the electrons in a molecule. The wave function is a high-dimensional entity, and it is therefore extremely difficult to capture all the nuances that encode how the individual electrons affect each other. Many methods of quantum chemistry in fact give up on expressing the wave function altogether, instead attempting only to determine the energy of a given molecule. This however requires approximations to be made, limiting the prediction quality of such methods.

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Hydrogen is a sustainable source of clean energy that avoids toxic emissions and can add value to multiple sectors in the economy including transportation, power generation, metals manufacturing, among others. Technologies for storing and transporting hydrogen bridge the gap between sustainable energy production and fuel use, and therefore are an essential component of a viable hydrogen economy. But traditional means of storage and transportation are expensive and susceptible to contamination. As a result, researchers are searching for alternative techniques that are reliable, low-cost and simple. More-efficient hydrogen delivery systems would benefit many applications such as stationary power, portable power, and mobile vehicle industries.

Now, as reported in the journal Proceedings of the National Academy of Sciences, researchers have designed and synthesized an effective material for speeding up one of the limiting steps in extracting from alcohols. The material, a , is made from tiny clusters of nickel anchored on a 2-D substrate. The team led by researchers at Lawrence Berkeley National Laboratory’s (Berkeley Lab) Molecular Foundry found that the catalyst could cleanly and efficiently accelerate the reaction that removes hydrogen atoms from a liquid chemical carrier. The material is robust and made from earth-abundant metals rather than existing options made from precious metals, and will help make hydrogen a viable energy source for a wide range of applications.

“We present here not merely a catalyst with higher activity than other nickel catalysts that we tested, for an important renewable energy fuel, but also a broader strategy toward using affordable metals in a broad range of reactions,” said Jeff Urban, the Inorganic Nanostructures Facility director at the Molecular Foundry who led the work. The research is part of the Hydrogen Materials Advanced Research Consortium (HyMARC), a consortium funded by the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy Hydrogen and Fuel Cell Technologies Office (EERE). Through this effort, five national laboratories work towards the goal to address the scientific gaps blocking the advancement of solid hydrogen storage materials. Outputs from this work will directly feed into EERE’s H2@Scale vision for affordable hydrogen production, storage, distribution and utilization across multiple sectors in the economy.

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