Advancing Basic Science for Humanity
08/26/2020 - Liquid Sunlight: Nanoscience Highlights
By Alan S. Brown
It’s an interesting time for nanoscience environmental news. First, a Caltech-led research consortium has received a $60 million grant to create liquid fuels—which are easy to store and use any time—from water, carbon dioxide greenhouse gases, and sunlight. Second, a team of researchers at UC Berkeley—working with ExxonMobil—have developed a more efficient and cheaper way to remove carbon dioxide from natural gas plant emissions. Third, a leading soil chemistry researcher is calling for new programs to learn more about how the soil stores and releases carbon dioxide. In other news, we discuss UC Berkeley’s new center for quantum computing, a way to image atoms more precisely using blurry images, and advances in graphene superconductivity.
- Liquid sunlight
A Caltech-led research consortium has received a five-year, $60 million grant to make liquid fuels from sunlight. Harry Atwater, a board member of the Kavli Nanoscience Institute at Caltech, will lead the endeavor. The group’s goal is to apply computational modeling and real-time ultrafast X-ray observations to streamline the complicated steps needed to convert sunlight, carbon dioxide, and water into hydrogen and other liquid fuels. Making fuel this way would recycle CO2 emissions back into new fuel without adding additional CO2 to the atmosphere. Unlike solar panels, which produce electricity only when the sun shines, liquid fuels are easy to store and use anytime.
- Stripping carbon
One way to slow global warming is to keep greenhouse gases from getting into the atmosphere. Natural gas power plants can do that by removing carbon from their emissions. Unfortunately, this is inefficient and expensive. A new approach developed by UC Berkeley, Lawrence Berkeley National Laboratory, and ExxonMobil could change the game. They have developed an ultrahigh porosity crystal called a metal-organic framework, or MOF, modified with amine molecules. It removes six times more carbon dioxide than the amine-based materials now used for the job. Equally important, they can strip the carbon off the MOF with low-temperature steam, by far the cheapest way to remove CO2 so operators can sequester it or put it to other uses. The research was led by Jeffrey Long, a UC Berkeley chemist, who teamed with Jeffrey Neaton, a member of the Kavli Energy NanoScience Institute (ENSI). MOFs were originally discovered by Omar Yaghi, an ENSI co-director.
- Carbon sinks
The world is full of carbon sinks that harbor carbon dioxide. One of the most important is soil, and we know surprisingly little about it, says Johannes Lehmann, a member of the Kavli Institute at Cornell for Nanoscale Science. The problem, Lehman says, is that soil and its mixture of microorganisms and carbon changes constantly. Because carbon can form so many different types of molecules, microbes are often confused about which forms to eat if there is very little of each kind. To improve our understanding, Lehmann and an international team of scientists are proposing the creation of new soil carbon-persistence models that look at how the interplay of time and space change the molecular structure of carbon in the soil. The models could improve global climate models and help agronomists develop better ways to encourage soil to absorb carbon from the atmosphere.
- Quantum leap
The National Science Foundation has awarded UC Berkeley $25 million over five years to establish a multi-university quantum science and engineering institute. The center will focus on developing software for quantum computers and training a future quantum workforce. The emerging quantum computers, which work by managing relationships among “entangled” quantum objects, will require entirely new types of algorithms to solve problems. Quantum computers could make it possible to factor large numbers, encrypt and decrypt data, search databases, and finding optimal solutions for problems. Another potential use is designing molecules to fight disease. One of the institute’s new co-directors is Birgitta Whaley, a member of the Kavli Energy NanoScience Institute and co-director of the Berkeley Quantum Information & Computation Center, who focuses on quantum biology.
- Blurrier is better
Microscopes are supposed to magnify and resolve tiny things, so every detail is crystal clear. That is a problem when using electron microscopes to peer at atoms. To get the best resolution, scientists must shower the sample with lots of electrons, but use too many and they fry the sample. The answer, according to David Mueller, co-director of the Kavli Institute at Cornell for Nanoscale Science, is a new set of algorithms. It achieves picometer (one-trillionth of a meter) precision using fewer electrons so it will not damage samples so easily—and it is faster and more efficient. The surprising thing about the new technique is that it works by defocusing the detector and blurring the beam. It then uses the algorithms to recover the shape of the blurred image. The method let Mueller’s team record data four times faster at double the resolution.
- No magic needed
In 2018, researchers made a surprising discovery: place two sheets of single-atom-thick graphene atop one another and rotate one 1.05 degrees and at some voltages they become superconducting. Change the voltage and they turn into an insulator. For the past two years, physicists and materials scientists have been trying to understand why these two states—superconductivity, where electrons move without resistance, and insulation, where electrons do not move at all—are so intimately related. Now researchers led by Stevan Nadj-Perge, a member a member of the Kavli Nanoscience Institute at Caltech, has taken an interesting step forward. He found that he can induce superconductivity at different angles simply by stacking graphene on an atomically thin sheet of tungsten diselenide. His work suggests there is still a lot to learn about graphene.