Hydrogen From Sunlight

Series of four still images from a sample video showing how a photoreactor from Rice University splits water molecules and generates hydrogen when stimulated by simulated sunlight. Credit: Mohite lab/Rice University

Rice University engineers can turn sunlight into hydrogen with record-breaking efficiency thanks to a device that combines next-generation halide perovskite semiconductors with electrocatalysts in a single, durable, cost-effective and scalable device.

The new technology is a significant step forward for clean energy and could serve as a platform for a wide range of chemical reactions that use solar-harvested electricity to convert feedstocks into fuels.

The lab of chemical and biomolecular engineer Aditya Mohite built the integrated photoreactor using an anticorrosion barrier that insulates the semiconductor from water without impeding the transfer of electrons.

According to a study published in Nature Communications, the device achieved a 20.8% solar-to-hydrogen conversion efficiency.

"Using sunlight as an energy source to manufacture chemicals is one of the largest hurdles to a clean energy economy," said Austin Fehr, a chemical and biomolecular engineering doctoral student and one of the study's lead authors. 

"Our goal is to build economically feasible platforms that can generate solar-derived fuels. Here, we designed a system that absorbs light and completes electrochemical water-splitting chemistry on its surface."

The device is known as a photoelectrochemical cell because the absorption of light, its conversion into electricity and the use of the electricity to power a chemical reaction all occur in the same device. Until now, using photoelectrochemical technology to produce green hydrogen was hampered by low efficiencies and the high cost of semiconductors.  READ MORE...

Coldest Matter in The Universe

An illustration shows trapped ytterbium atoms cooled to temperatures about 3 billion times 

colder than deep space (Image credit: Ella Maru Studio/Courtesy of K. Hazzard/Rice University)

A team of researchers has cooled matter to within a billionth of a degree of absolute zero, colder than even the deepest depths of space ,  far away from any stars.


Interstellar space never gets this cold due to the fact that it is evenly filled with the cosmic microwave background (CMB), a form of radiation left over from an event that occurred shortly after the Big Bang when the universe was in its infancy. 

The chilled matter is even colder than the coldest known region of space, the Boomerang Nebula, located 3,000 light-years from Earth, which has a temperature of just one degree above absolute zero.

The experiment, run at the University of Kyoto in Japan and used fermions, which is what particle physicists call any particle that makes up matter, including electrons, protons and neutrons. 

The team cooled their fermions — atoms of the element ytterbium — to around a billionth of a degree above absolute zero, the hypothetical temperature at which all atomic movement would cease.

"Unless an alien civilization is doing experiments like these right now, anytime this experiment is running at Kyoto University it is making the coldest fermions in the universe," Rice University researcher Kaden Hazzard, who took part in the study, said in a statement(opens in new tab).  READ MORE...

Preventing Cancer

A new theory suggests that mutations have few straightforward ways to establish themselves in cells and cause tumors.

For many researchers, the road to cancer prevention is long and difficult, but a recent study by Rice University scientists suggests that there may be shortcuts.

A theoretical framework is being developed by Rice scientist Anatoly Kolomeisky, postdoctoral researcher Hamid Teimouri, and research assistant Cade Spaulding that will explain how cancers brought on by several genetic mutations might be more readily recognized and perhaps prevented.

It does this by detecting and ignoring transition pathways that don’t significantly contribute to the fixation of mutations in a cell that later becomes a tumor.

The study, which was published on May 13th, 2022 in the Biophysical Journal, details their analysis of the effective energy landscapes of cellular transformation pathways connected to a number of cancers. 

The ability to narrow the number of paths to those most likely to initiate cancer could help in the development of strategies to interrupt the process before it begins.

“In some sense, cancer is a bad-luck story,” said Kolomeisky, a professor of chemistry and of chemical and biomolecular engineering. 

“We think we can decrease the probability of this bad luck by looking for low-probability collections of mutations that typically lead to cancer. Depending on the type of cancer, this can range between two mutations and 10.”

Calculating the effective energies that govern interactions in biomolecular systems may help anticipate how they will behave. The theory is widely used to anticipate how a protein will fold based on the sequence of its constituent atoms and how they interact.    READ MORE...

A Selfish Link

 FROM RICE UNIVERSITY...

One of nature's most prolific cannibals could be hiding in your pantry, and biologists have used it to show how social structure affects the evolution of selfish behavior.

Researchers revealed that less selfish behavior evolved under living conditions that forced individuals to interact more frequently with siblings. While the finding was verified with insect experiments, Rice University biologist Volker Rudolf said the evolutionary principle could be applied to study any species, including humans.

In a study published online this week in Ecology Letters, Rudolf, longtime collaborator Mike Boots of the University of California, Berkeley, and colleagues showed they could drive the evolution of cannibalism in Indian meal moth caterpillars with simple changes to their habitats.

Also known as weevil moths and pantry moths, Indian meal moths are common pantry pests that lay eggs in cereals, flour and other packaged foods. As larvae, they're vegetarian caterpillars with one exception: They sometimes eat one another, including their own broodmates.

In laboratory tests, researchers showed they could predictably increase or decrease rates of cannibalism in Indian meal moths by decreasing how far individuals could roam from one another, and thus increasing the likelihood of "local" interactions between sibling larvae. In habitats where caterpillars were forced to interact more often with siblings, less selfish behavior evolved within 10 generations.

Rudolf, a professor of biosciences at Rice, said increased local interactions stack the deck against the evolution of selfish behaviors like cannibalism.  READ MORE