New material tries to solve global problems

Singaporean scientists have discovered a new low-cost material that could do everything from cleaning water to producing clean energy to even healing wounds in the form of a bandage

A new wonder material that can generate hydrogen, produce clean water and even create energy. Science fiction? Hardly, and there’s more - It can also desalinate water, be used 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.

Scientists at Nanyang Technological University (NTU), led by Darren Sun have succeeded in developing a single, revolutionary nanomaterial that can do all the above and at very low cost compared to existing technology.

This breakthrough which has taken Sun five years to develop is dubbed the Multi-use Titanium Dioxide (TiO2). It is formed by turning titanium dioxide crystals into patented nanofibres, which can then be easily fabricated into patented flexible filter membranes which include a combination of carbon, copper, zinc or tin, depending on the specific end product needed.

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).

“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,” 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.”

Discovery of the material

Sun had initially used titanium dioxide with iron oxide to make anti-bacterial water filtration membranes to solve biofouling - bacterial growth which clogs up the pores of membranes, obstructing water flow.

While developing the membrane, Sun’s 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, a precious metal that is both expensive and rare.

“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 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.”

Depending on the type of wastewater, the amount of hydrogen generated can be as much as 200 millilitres in an hour. Also to increase hydrogen production, more nanomaterial can be used in larger amounts of wastewater.

With its anti-microbial properties and low cost, the membrane can also be used to make breathable anti-bacterial bandages, which would not only prevent infections and tackle infection at open wounds, but also promote healing by allowing oxygen to permeate through the plaster.

The membrane’s material properties are also similar to polymers used to make plastic bandages currently sold on the market. The material when with other materials or made into another form such as crystals, it can have other uses, such as in solar cells.

1 / 1