Every living cell in our body can do it: covered with a thin membrane known as a cell membrane or nanomembrane, the cells can deliberately let specific substances in and out. Although it is thousands of times thinner than a human hair, this nanomembrane has an extremely complex structure and function. Three Nobel prizes have already been awarded for improving our understanding of these nanomembranes.

Microscopic ducts convey water, electrical charges and nutrients around and in doing so, create an equilibrium within the cell. However, we still do not know about many of the functions and structural details, as it is only the water and proton exchange that has been researched in depth. “These extremely fine cell membrane ducts, with the ability to selectively convey protons, function in exactly the same way as fuel cells created by humans,” explains Dr Werner Brenner, “only this naturally occurring process is considerably more efficient.”

Fuel cells: an alternative to oil

Today, fuel cells are seen as a serious alternative to oil, which until now has been the basis for electrical energy and mobility. However, the earth’s oil reserves are rapidly running out, under economic pressure to drill ever deeper into the seabed. Oil combustion also generates CO2, soot and other residues. The only waste product from a fuel cell is water.

The EU project focuses on the design of the main component of every fuel cell — i.e. the membrane — with the intention of conveying protons more efficiently than in previous solutions. “The first results have been encouraging. It will not be easy, but it is possible. Nature has been producing these structures for billions of years and their effectiveness can be seen in every living organism. Our task is to transfer the structure of these natural nanoducts to an artificial nanomembrane, which is itself only a few hundred nanometres thick,” explains Dr Jovan Matovic.

A wide range of scientific approaches are required for this project, ranging from solid state physics and nanotechnology through to chemistry. Therefore, international cooperation with six universities, research institutes and businesses is also of great importance. The EU project is being coordinated by the TU Vienna research team of Assist Prof Dr Werner Brenner, Dr Jovan Matovic and Dr Nadja Adamovic at the Institute of Sensor and Actuator Systems.

The University research team is confident: “The results of this project should have far-reaching significance for our society. If we succeed in creating the nanoducts exactly as planned, then completely different fields of application will open up, such as the accurately controlled delivery of medicine, water desalination or even new types of sensors,” explains Dr Nadja Adamovic, “In this project, the boundaries between “artificial and “natural” are becoming even more blurred.”

Vienna University of Technology (2010, October 6). Nano design, just like in nature. ScienceDaily http://www.sciencedaily.com­ /releases/2010/06/100615151705.htm

The Original Post is Located Here: Nano Design, Just Like in Nature

The technical name for a fuel cell is an electrochemical energy conversion device. A fuel cell converts the chemicals hydrogen and oxygen into water, and in the process it produces electricity. Other electrochemical devices that are in use these days and for many decades is the well-known battery. The distinguishing difference between a simple battery and a fuel cell is that all the chemicals are stored inside the battery. The battery in turn converts those chemicals into electricity but in due course it “goes dead” as the chemicals are used up and at times you can either throw it away or recharge it.

Then again with a fuel cell, chemicals continually flow into the cell so as long as there is a flow of chemicals into the cell; the electricity flows out of the fuel cell. Combustion engines the gasoline engine burn fuels and batteries converted chemical energy back into electrical energy when needed. However, fuel cells should do both tasks more efficiently.

Simply put the construction and materials in a fuel cell release electrons from the hydrogen gas creating electricity and the waste product after the electricity is used to power an electrical device is water, formed with the negative hydrogen and the oxygen.This reaction in a single fuel cell produces only about 0.7 volts. To get this voltage up to a reasonable level, several separate fuel cells must be combined to form a fuel-cell stack.

However one major problem with using hydrogen is that it is cannot be stored easily for consumer use. Among the other alternatives, it could be natural gas, propane, and methanol gas. The main objective of using fuel cell technology is pollution reduction. Fuel cell is also very efficient; 80% of the fuel use in these cells is converted into usable energy as compared to only 20% for a gasoline powered engine and about 30% overall for a battery powered electric vehicle.

Evidently there is no question that the fuel cell holds greater promise for the future. However, the fuel cell technology must still gather all the pieces of finding the right ‘fuel’ source that is both easy to store and deliver to the consumer, efficiency of the vehicle using fuel cells, and the cost for the total package.

The Original Post is Located Here: A Basic Overview Of Fuel Cell Technology

Scanning electron microscope image of typical titania nanotubes for a photocatalytic cell to produce hydrogen gas from water

A research team from Northeastern University and the National Institute of Standards and Technology (NIST) has discovered, serendipitously, that a residue of a process used to build arrays of titania nanotubes-a residue that wasn’t even noticed before this-plays an important role in improving the performance of the nanotubes in solar cells that produce hydrogen gas from water. Their recently published results* indicate that by controlling the deposition of potassium on the surface of the nanotubes, engineers can achieve significant energy savings in a promising new alternate energy system.

Titania (or titanium dioxide) is a versatile chemical compound best known as a white pigment. It’s found in everything from paint to toothpastes and sunscreen lotions. Thirty-five years ago Akira Fujishima startled the electrochemical world by demonstrating that it also functioned as a photocatalyst, producing hydrogen gas from water, electricity and sunlight. In recent years, researchers have been exploring different ways to optimize the process and create a commercially viable technology that, essentially, transforms cheap sunlight into hydrogen, a pollution-free fuel that can be stored and shipped.

Increasing the available surface area is one way to boost a catalyst’s performance, so a team at Northeastern has been studying techniques to build tightly packed arrays of titania nanotubes, which have a very high surface to volume ratio. They also were interested in how best to incorporate carbon into the nanotubes, because carbon helps titania absorb light in the visible spectrum. (Pure titania absorbs in the ultraviolet region, and much of the ultraviolet is filtered by the atmosphere.)

This brought them to the NIST X-ray spectroscopy beamline at the National Synchrotron Light Source (NSLS)**. The NIST facility uses X-rays that can be precisely tuned to measure chemical bonds of specific elements, and is at least 10 times more sensitive than commonly available laboratory instruments, allowing researchers to detect elements at extremely low concentrations. While making measurements of the carbon atoms, the team noticed spectroscopic data indicating that the titania nanotubes had small amounts of potassium ions strongly bound to the surface, evidently left by the fabrication process, which used potassium salts. This was the first time the potassium has ever been observed on titania nanotubes; previous measurements were not sensitive enough to detect it.

The result was mildly interesting, but became much more so when the research team compared the performance of the potassium-bearing nanotubes to similar arrays deliberately prepared without potassium. The former required only about one-third the electrical energy to produce the same amount of hydrogen as an equivalent array of potassium-free nanotubes. “The result was so exciting,” recalls Northeastern physicist Latika Menon, “that we got sidetracked from the carbon research.” Because it has such a strong effect at nearly undetectable concentrations, Menon says, potassium probably has played an unrecognized role in many experimental water-splitting cells that use titania nanotubes, because potassium hydroxide is commonly used in the cells. By controlling it, she says, hydrogen solar cell designers could use it to optimize performance.

* C. Richter, C. Jaye, E. Panaitescu, D.A. Fischer, L.H. Lewis, R.J. Willey and L. Menon. Effect of potassium adsorption on the photochemical properties of titania nanotube arrays. J. Mater. Chem., published online as an Advanced Article, March 27, 2009. DOI: 10.1039/b822501j

** The NSLS is part of the Department of Energy’s Brookhaven National Laboratory.

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The Original Post is Located Here: Improving Performance of Nanotubes in Solar Cells that Produce Hydrogen Gas from Water

Fuel Cell Schematic

Fuel cells are electrochemical devices that convert a fuel’s chemical reaction in an electrolyte directly into electrical energy from fuel (on the anode side) and an oxidant (on the cathode side).

While they are similar to batteries in that they have no moving parts, batteries store their energy whereas fuel cells can produce electricity continuously as long as there is fuel and air.

As fuel cells combine a fuel (typically hydrogen) and an oxidant the resultant energy is captured directly and does not require the usual conversion of heat or movement to electrical energy and therefore is extremely efficient and pollutant emmissions are practically zero.

Many combinations of fuel and oxidant are possible, however, the most common combination is a a hydrogen cell that uses hydrogen as fuel and oxygen (usually from air) as an oxidant. Other fuels available include hydrocarbons and alcohols, while other oxidants used include chlorine and chlorine dioxide.
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The Original Post is Located Here: What is a Fuel Cell?