Gilded fuel cells boost electric car efficiency

To make modern-day fuel cells less expensive and more powerful, a team led by Johns Hopkins chemical engineers has drawn inspiration from the ancient Egyptian tradition of gilding. Egyptian artists at the time of King Tutankhamun often covered cheaper metals (copper, for instance) with a thin layer of a gleaming precious metal such as gold to create extravagant masks and jewelry. In a modern-day twist, the Johns Hopkins-led researchers have applied a tiny coating of costly platinum just one nanometer thick—100,000 times thinner than a human hair—to a core of much cheaper cobalt. This microscopic marriage could become a crucial catalyst in new fuel cells that generate electric current to power cars and other machines.

The new fuel cell design would save money because it would require far less platinum, a very rare and expensive metal that is commonly used as a catalyst in present-day fuel-cell electric cars. The researchers, who published their work earlier this year in Nano Letters, say that by making electric cars more affordable, this innovation could curb the emission of carbon dioxide and other pollutants from gasoline– or diesel-powered vehicles.

This technique could accelerate our launch out of the fossil fuel era,” said Chao Wang, a Johns Hopkins assistant professor in the Department of Chemical and Biomolecular Engineering and senior author of the study. “It will not only reduce the cost of fuel cells. It will also improve the energy efficiency and power performance of clean electric vehicles powered by hydrogen.”

In their journal article, the authors tipped their hats to the ancient Egyptian artisans who used a similar plating technique to give copper masks and other metallic works of art a lustrous final coat of silver or gold.The idea,” Wang said, “is to put a little bit of the precious treasure on top of the cheap stuff.”

He pointed out that platinum, frequently used in jewelry, also is a critical material in modern industry. It catalyzes essential reactions in activities including petroleum processing, petrochemical synthesis, and emission control in combustion vehicles, and is used in fuel cells. But, he said, platinum’s high cost and limited availability have made its use in clean energy technologies largely impractical—until now.

Source: https://hub.jhu.edu/

Bubble-Pen To Build Nanocomputer, Sensor, Solar Panel…

Researchers in the Cockrell School of Engineering at The University of Texas at Austin have solved a problem in micro- and nanofabrication — how to quickly, gently and precisely handle tiny particles — that will allow researchers to more easily build tiny machines, biomedical sensors, optical computers, solar panels and other devices. They have developed a device and technique, called bubble-pen lithography, that can efficiently handle nanoparticles — the tiny pieces of gold, silicon and other materials used in nanomanufacturing. The new method relies on microbubbles to inscribe, or write, nanoparticles onto a surface.

A research team led by Texas Engineering assistant professor Yuebing Zheng has invented a way to handle these small particles and lock them into position without damaging them. Using microbubbles to gently transport the particles, the bubble-pen lithography technique can quickly arrange particles in various shapes, sizes, compositions and distances between nanostructures.

bubble-pen litho

The ability to control a single nanoparticle and fix it to a substrate without damaging it could open up great opportunities for the creation of new materials and devices,” Zheng said. “The capability of arranging the particles will help to advance a class of new materials, known as metamaterials, with properties and functions that do not exist in current natural materials.

The team, which includes Cockrell School associate professor Deji Akinwande and professor Andrew Dunn, describe their patented device and technique in a paper published in Nano Letters.

Source: https://news.utexas.edu/

How To Extract Easily Gold From The Waste

Research by scientists at the University of York has demonstrated an innovative way of using a gel to extract precious metals such as silver and gold from waste and convert them into conducting nanoparticles to form a hybrid nanomaterial potentially suitable for a range of high-tech applications.

Discarded electronic devices are an ever-increasing waste stream containing high-value precious metals such as silver and gold.  Making use of this resource was the inspiration for the research by a team from the Department of Chemistry at York. Professor David Smith and Babatunde Okesola, a PhD student supported by The Wild Fund, discovered that their self-assembling gels derived from sorbitol, a simple sugar, could selectively extract precious metals from complex mixtures of other metals typical of the electronics or mining industries.

 

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On exposure to the gel, not only were the precious metals selectively extracted, but they were also then converted into conducting nanoparticles via an in situ chemical reduction process, caused by the nanofibres of the gel network.  These conducting nanoparticles become embedded in the gel giving it enhanced electrical conductance.

Babatunde Okesola said: “Importantly, gels have properties of both solids and liquids so these conducting gels are potentially ideal to bridge between the soft, wet world of biology and the hard, dry world of electronics.  Being able to ‘wire up’ this interface will be of increasing importance in future technologies.
Dr Smith added: “We hope to go on and test our gels using real-world electronic waste, and also explore the potential applications of the resulting materials at the interface between biology and electronics.

Source: https://www.york.ac.uk/

New Eco-Friendly Gold Rush

Northwestern University scientists have struck gold in the laboratory. They have discovered an inexpensive and environmentally benign method that uses simple cornstarch — instead of cyanide — to isolate gold from raw materials in a selective manner. This green method extracts gold from crude sources and leaves behind other metals that are often found mixed together with the crude gold. The new process also can be used to extract gold from consumer electronic waste. Current methods for gold recovery involve the use of highly poisonous cyanides, often leading to contamination of the environment. Nearly all gold-mining companies use this toxic gold leaching process to sequester the precious metal.
goldrush
A modern day gold rush! A new method developed at Northwestern bypasses the use of toxic cyanide for gold purification by using an eco-friendly sugar (cyclodextrin) derived from starch
The elimination of cyanide from the gold industry is of the utmost importance environmentally,” said Sir Fraser Stoddart, the Board of Trustees Professor of Chemistry in the Weinberg College of Arts and Sciences. “We have replaced nasty reagents with a cheap, biologically friendly material derived from starch.
Source: http://www.northwestern.edu/

Gold, Land Of Promise For Nanotechnology

Gold has scientists excited and not for its more than $US1600 an ounce price tag.
Deputy Pro Vice-Chancellor (International) Suresh Bhargava from RMIT University – Australia -says for centuries gold has been defined as a noble metal, or a stable one that’s resistant to corrosion and oxidisation. “But the same metal, when it comes to nano forms, is full of fantastic properties,” Professor Bhargava says.
Nano sizes can be easier to comprehend when people realise a human hair is about 80,000 times bigger than a nano particle, the molecular biologist says. One of Prof Bhargava’s projects is using nano-engineered flecks of gold in a sensor to attract and measure one of the world’s most poisonous air pollution substances, mercury.

Mercury is a very toxic element. Sixty thousand babies in the US alone are born each year with mercury-related diseases,” he says.
The sensor is almost ready for commercialisation and they are also working on ways to remove the toxic element from the air.
It is not far away,” he told AAP this week.
Source: http://www.theaustralian.com.