March 21, 2013
New Nanomaterial Is Best Thing Since Sliced Bread
Lee Rannals for redOrbit.com - Your Universe Online
Scientists have succeeded in creating a new material that is capable of generating hydrogen, producing clean water and creating energy.
Nanyang Technological University (NTU) researchers created a single nanomaterial that can be used as a flexible water filtration membrane, to help recover energy from desalination waste brine, be made into flexible solar cells, and can double the lifespan of lithium ion batteries.
The Multi-use Titanium Dioxide (TiO2) is a cheap and abundant material formed by turning titanium dioxide crystals into patented nanofibers, which can be fabricated into patented filter membranes.
Associate Professor Darren Sun, who has led the research, says TiO2 could have immense potential to help tackle ongoing global challenges in energy and environmental issues. As the world continues to grow, there will be a massive increase in the global demand for energy and food by 50 percent and 30 percent for drinking water.
"While there is no single silver bullet to solving two of the world´s biggest challenges: cheap renewable energy and an abundant supply of clean water; our single multi-use membrane comes close, with its titanium dioxide nanoparticles being a key catalyst in discovering such solutions," Prof Sun said. "With our unique nanomaterial, we hope to be able to help convert today´s waste into tomorrow´s resources, such as clean water and energy."
Sun and his colleagues discovered TiO2 while using titanium dioxide with iron oxide to make anti-bacterial water filtration membranes to solve biofouling, which is bacterial growth that clogs up the pores of membranes and obstructs water flow.
The team discovered that TiO2 could act as a photocatalyst, turning wastewater into hydrogen and oxygen under sunlight while still producing clean water. This water-splitting effect is caused by Platinum.
"With such a discovery, it is possible to concurrently treat wastewater and yet have a much cheaper option of storing solar energy in the form of hydrogen so that it can be available any time, day or night, regardless of whether the sun is shining or not, which makes it truly a source of clean fuel," said Prof Sun.
He said now they are achieving a very high efficiency about three times more than if they used platinum, but at a lower cost.
"In addition, we can concurrently produce clean water for close-to-zero energy cost, which may change our current water reclamation system over the world for future liveable cities," Sun said.
The discovery of the material was published in the journal Water Research, where they wrote about how a small amount of the nanomaterial can generate 1.53 milliliter of hydrogen in an hour.
The material can also be used to make breathable anti-bacterial bandages, which could help prevent infections. The membrane's material properties are similar to polymers used to make plastic bandages currently sold on the market.
As far as energy goes, TiO2 can be used in Lithium ion batteries commonly used in electronic devices. Preliminary results from Sun and his colleague's research shows that when titanium dioxide sphere-like nanoparticles modified with carbon are used as the anode, it can double the capacity of the battery. They wrote specifically about this research in the Journals of Materials Chemistry.
Researchers from CQUniversity, Australia wrote about similar findings with titanium dioxide in January last year. This team reported in the journal BMC Microbiology about using TiO2 to enhance the sun's natural disinfection properties, helping to reduce the need for expensive antibiotics or poisonous chemicals.
"Other people have looked at using TiO2 as an enhancer of solar disinfection, but they either used a suspension of TiO2 particles in water, or artificial UV to test their reactors," Prof Rob Reed, one of the team who performed this work said. "Our TTFBR technology is very effective at killing pathogens at high levels of natural sunlight and consequently is particularly suited to countries with sunny climates and is especially useful to developing countries where sunlight is abundant but other resources are scarce."