A new titanium-based nano-technology wonder material can generate hydrogen, produce clean water and even create energy.
It is the stuff of science fiction; but it is apparently for real. And the science is happening at the Nanyang University in Singapore.
And there’s more as it is claimed that the material can also be used to desalinate water, employed as flexible water filtration membranes, help recover energy from desalination waste brine, be made into flexible solar cells and can also double the lifespan of lithium ion batteries.
With its superior bacteria-killing capabilities, it can also be used to develop a new type of antibacterial bandage.
The Nanyang team is led by associate professor, Darren Sun, and, in a nutshell, they have developed a single nano-material that can do all of the above and, it is said, at very low cost compared to existing technology.
This breakthrough, which has taken Prof Sun five years to develop, is known as “Multi-use Titanium Dioxide (TiO2)”.
It is formed by converting titanium dioxide crystals into patented nano-fibres, which can then be easily fabricated into patented flexible filter membranes which incorporate a combination of carbon, copper, zinc or tin, depending on the specific end application.
Titanium dioxide is a cheap and abundant material, which has been scientifically proven to have the ability to accelerate a chemical reaction (photocatalytic) and is also able to bond easily with water (hydrophilic).
More than 70 scientific papers on Prof Sun’s work on titanium dioxide have been published over the last five years, the latest being papers published in Water Research, Energy and Environmental Science, and Journal of Materials Chemistry.
Prof Sun, 52, from NTU’s School of Civil and Environmental Engineering, said such a low-cost and easily-produced nanomaterials is expected to have immense potential to help tackle ongoing global challenges in energy and environmental issues.
With the world’s population expected to hit 8.3billion by 2030, there will be a massive increase in the global demand for energy and food by 50% and 30% for drinking water (Population Institute report, titled 2030: The “Perfect Storm” Scenario).
Commenting on the work, Prof Sun said: “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.
“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.”
Prof Sun’s multi-use titanium dioxide can:
o concurrently produce both hydrogen and clean water when exposed to sunlight
o be made into a low-cost flexible filtration membrane that is anti-fouling
o desalinate water as a high flux forward osmosis membrane
o recover energy from waste desalination brine and wastewater
o be made into a low-cost flexible solar cell to generate electricity
o doubles battery life when used as anode in lithium ion battery
o kill harmful microbial, leading to new antibacterial bandages
The origins of the new material lie in Prof Sun’s earlier work that initially used titanium dioxide with iron oxide to make anti-bacterial water filtration membranes to solve bio-fouling – bacterial growth which clogs up the pores of membranes, obstructing water flow.
While developing the membrane, his team also discovered that it could act as a photocatalyst, turning wastewater into hydrogen and oxygen under sunlight while still producing clean water.
Such a water-splitting effect is usually caused by platinum, which is precious, rare and expensive.
“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.
“As of now, we are achieving a very high efficiency of about three times more than if we had used platinum, but at a much lower cost, allowing for cheap hydrogen production. 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.”
Turning to hydrogen and clean water, the team demonstrated that a small amount of nanomaterial (0.5 grams of titanium dioxide nanofibres treated with copper oxide), can generate 1.53ml of hydrogen in an hour when immersed in one litre of wastewater. This amount of hydrogen produced is three times more than when platinum is used in the same situation.
Depending on the type of wastewater, the amount of hydrogen generated can be as much as 200ml in an hour. Also to increase hydrogen production, more nano-material can be used in larger amounts of wastewater.
As for photovoltaics and lithium-ion batteries the impacts are considered just as dramatic.
Prof Sun and his team of 20, which includes six undergraduates, 10 PhD students and four researchers, are now working to further develop the material while concurrently spinning off a start-up company to commercialise the product.
They are also looking to collaborate with commercial partners to speed up the commercialisation process.