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/

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/

3D Printing: How To Control the Structure of Metal

Researchers at the Department of Energy’s Oak Ridge National Laboratory (ORNL) have demonstrated an additive manufacturing method to control the structure and properties of metal components with precision unmatched by conventional manufacturing processes. Ryan Dehoff, staff scientist and metal additive manufacturing lead at the Department of Energy’s Manufacturing Demonstration Facility at ORNL, presented the research this week in an invited presentation at the Materials Science & Technology 2014 conference in Pittsburgh.

3D prining metalORNL researchers have demonstrated the ability to precisely control the structure and properties of 3-D printed metal parts during formation. The electron backscatter diffraction image shows variations in crystallographic orientation in a nickel-based component, achieved by controlling the 3-D printing process at the microscale

We can now control local material properties, which will change the future of how we engineer metallic components,” Dehoff said. “This new manufacturing method takes us from reactive design to proactive design. It will help us make parts that are stronger, lighter and function better for more energy-efficient transportation and energy production applications such as cars and wind turbines.”
We’re using well established metallurgical phenomena, but we’ve never been able to control the processes well enough to take advantage of them at this scale and at this level of detail,” said Suresh Babu, the University of Tennessee-ORNL Governor’s Chair for Advanced Manufacturing. “As a result of our work, designers can now specify location specific crystal structure orientations in a part.”

Source: http://www.ornl.gov

Revolutionary Method To Convert Sunlight into Energy

A new method of harvesting the Sun’s energy is emerging, thanks to scientists at UC Santa Barbara‘s Departments of Chemistry, Chemical Engineering, and Materials. Though still in its infancy, the research promises to convert sunlight into energy using a process based on metals that are more robust than many of the semiconductors used in conventional methods.
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When nanostructures, such as nanorods, of certain metals are exposed to visible light, the conduction electrons of the metal can be caused to oscillate collectively, absorbing a great deal of the light,” said Martin Moskovits, professor of chemistry at UCSB.. “This excitation is called a surface plasmon.
It is the first radically new and potentially workable alternative to semiconductor-based solar conversion devices to be developed in the past 70 years or so,” said Moskovits.
Source: http://www.ia.ucsb.edu/