In a new paper, researchers describe the underlying mechanisms involved in creating a widely used class of quantum dots that use cadmium and selenium compounds as their molecular precursors.

For more than 30 years, researchers have been creating quantum dots—tiny, crystalline, nanoscale semiconductors with remarkable optical and electronic properties.

They’ve applied them to improve television sets, for example, to greatly enhance color. A host of other applications are in the works, involving integrated circuits, solar cells, computing, medical imaging, and inkjet printing, among others.

But quantum dot synthesis has occurred largely by trial and error, because little has been understood about how the chemicals involved in making quantum dots—some highly toxic—actually interact to form the resulting nanoparticles. The new research may change that, revealing more about the process of quantum dot formation.

Ironically, the team also discovered that, at one point during this process, the safer, more controllable compounds now employed decompose into the same highly toxic compounds that were used in initial quantum dot production 30 years ago.

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A team of researchers from MIT recently demonstrated a new electrochemical method to study thermodynamic processes in an ultra-high temperature molten oxide. In an effort to find new insights into the thermodynamic properties of refractory materials, researchers have developed a container-less electrochemical method to study thermodynamic properties of materials like aluminum oxide, which melts at temperatures above 2,000 degrees Celsius.

The finding were reported in the open access paper, “Electrochemical Study of a Pendant Molten Alumina Droplet and Its Application for Thermodynamic Property Measurements of Al-Ir,” which was recently published in the Journal of The Electrochemical Society.

“We have a new technique which demonstrates that the rules of electrochemistry are followed for these refractory melts,” says senior author Antoine Allanore, an associate professor of metallurgy and member of ECS. “We have now evidence that these melts are very stable at high temperature, they have high conductivity.”

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New research is building a bridge from nature’s chemistry to greener, more efficient synthetic chemistry.

Researchers analyzed biocatalysts evolved by nature for their effectiveness in a variety of synthetic chemical reactions. The results, published in Nature Chemistry, open the door to promising practices for chemists, pointing to not only more efficient but also more powerful tools for chemists.

The researchers started with microorganisms that have, over the millennia, developed complex chemical reactions to create molecules with important biological activity for various purposes, such as defense mechanisms. The scientists then analyzed the chemical pathways that give rise to these potentially useful molecules to determine how they can be repurposed to create compounds synthetically in the lab.

“Nature has evolved catalytic tools that would enable chemists to build molecules that we can’t easily build just using traditional chemistry,” says senior study author Alison Narayan, assistant professor at the University of Michigan Life Sciences Institute. “Our work bridges the two worlds of biosynthesis and synthetic chemistry.”

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By: John Staser, division vice chair and Assistant Professor at Ohio University

As vice chair of the Industrial Electrochemistry and Electrochemical Engineering Division, it is with great pleasure that I introduce the summer 2017 edition of Interface.

The authors of the articles you are about to read all worked tirelessly, and we owe them acknowledgement and significant gratitude for putting this issue together. Without their contributions, we would not be able to deliver the consistent quality of content that you expect in Interface.

We as a division hope to highlight the diverse activities of our members.

In the following pages you will find articles authored by industrial and academic members, with foci ranging from environmental applications to mathematical modeling to large-scale industrial production of metals. Such breadth is evidence that our division’s activities, as has been the case in the past, are ever evolving.

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New paper-based, point-of-care diagnostic tools could lead to improvements in device cost, weight, and flexibility. The recently developed SPEDs, or self-powered, paper-based electrochemical device, can detect biomarkers such as glucose and white blood cells, all while remaining easy to read for non-experts.

The Purdue University research team behind this project believes it could be applicable for patients in regions where access to sophisticated medical equipment is limited.

“You could consider this a portable laboratory that is just completely made out of paper, is inexpensive and can be disposed of through incineration,” says Ramses V. Martinez, an assistant professor of industrial and biomedical engineering at Purdue University. “We hope these devices will serve untrained people located in remote villages or military bases to test for a variety of diseases without requiring any source of electricity, clean water, or additional equipment.”

Researchers from MIT have developed a new way to extract copper by separating the commercially valuable metal from sulfide minerals in one step without harmful byproducts. The goal of this new process is to simplify metal production, thereby eliminating harmful byproducts and driving down costs.

To achieve this result, the team used a process called molten electrolysis. Electrolysis is a common technique used to break apart compounds, often seen in water splitting to separate hydrogen from oxygen. The same process is also used in aluminum production and as a final step in copper production to remove any impurities. However, electrolysis in copper production is a multistep process that emits sulfur dioxide.

This from MIT:

Contrary to aluminum, however, there are no direct electrolytic decomposition processes for copper-containing sulfide minerals to produce liquid copper.

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Researchers from Purdue University are making headway on solving issues in electrolyzers and fuel cell development by gaining new insight into electrocatalysts.

Electrocatalysts are key in promoting the chemical reactions that happen in both fuel cells and electrolyzers. However, while activating theses chemical reactions is crucial, the electrocatalysts tend to be unstable and can corrode when used in fuel cells and electrolyzers.

ECS member Jeffrey Greeley is looking to address this issue by identifying the structure for an active, stable electrocatalyst made of nickel nanoislands deposited on platinum.

“The reactions led to very stable structures that we would not predict by just looking at the properties of nickel,” Greeley says. “It turned out to be quite a surprise.”

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Using high pressure, scientists have created the first high-entropy metal alloy made of common metals to have a hexagonal close-packed (HCP) atomic structure.

This makes it lighter and stronger than comparable metal alloys with different structures.

Traditional alloys typically consist of one or two dominant metals with a pinch of other metals or elements thrown in. Classic examples include adding tin to copper to make bronze, or carbon to iron to create steel.

In contrast, “high-entropy” alloys consist of multiple metals mixed in approximately equal amounts. The result is stronger and lighter alloys that are more resistant to heat, corrosion, and radiation, and that might even possess unique mechanical, magnetic, or electrical properties.

Despite significant interest from material scientists, high-entropy alloys have yet to make the leap from the lab to actual products. One major reason is that scientists haven’t yet figured out how to precisely control the arrangement, or packing structure, of the constituent atoms.

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Hydrogen has many highly sought after qualities when it comes to clean energy sources. It is a simple element, high in energy, and produces nearly zero harmful emissions. However, while hydrogen is one of the most plentiful elements in the universe, it does not occur naturally as a gas. Instead, we find it combined with other elements, like oxygen in the form of water. For many researchers, water-splitting has been a way to isolate hydrogen for use in cars, houses, and other sustainable fuels.

But water-splitting requires an effective catalyst to speed up chemical reactions, while simultaneously preventing the gasses to recombine. Researchers from the DOE’s SLAC National Accelerator Laboratory believe they may have the answer with the new development of a molybdenum coating that can potentially improve water-splitting.

“When you split water into hydrogen and oxygen, the gaseous products of the reaction are easily recombined back to water and it’s crucial to avoid this,” says Angel Garcia-Esparza, lead author of the study. “We discovered that a molybdenum-coated catalyst is capable of selectively producing hydrogen from water while inhibiting the back reactions of water formation.”

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By: Mohammad S. Jalali, Massachusetts Institute of Technology

From social to natural and applied sciences, overall scientific output has been growing worldwide – it doubles every nine years.

Traditionally, researchers solve a problem by conducting new experiments. With the ever-growing body of scientific literature, though, it is becoming more common to make a discovery based on the vast number of already-published journal articles. Researchers synthesize the findings from previous studies to develop a more complete understanding of a phenomenon. Making sense of this explosion of studies is critical for scientists not only to build on previous work but also to push research fields forward.

My colleagues Hazhir Rahmandad and Kamran Paynabar and I have developed a new, more robust way to pull together all the prior research on a particular topic. In a five-year joint project between MIT and Georgia Tech, we worked to create a new technique for research aggregation. Our recently published paper in PLOS ONE introduces a flexible method that helps synthesize findings from prior studies, even potentially those with diverse methods and diverging results. We call it generalized model aggregation, or GMA.

Pulling it all together

Narrative reviews of the literature have long been a key component of scientific publications. The need for more comprehensive approaches has led to the emergence of two other very useful methods: systematic review and meta-analysis.

In a systematic review, an author finds and critiques all prior studies around a similar research question. The idea is to bring a reader up to speed on the current state of affairs around a particular research topic.

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