Purifying water by simulating photosynthesis

Water supplies are under threat in many regions of the planet. Assuring the supply of water to difficult-to-access urban and rural areas for over one billion people will be a major challenge in the not-too-distant future.

Nanoparticles of titanium dioxide and gold

Recent advances by a group of Chinese researchers into water purification methods, using renewable energy sources, has opened up a promising line of research that could solve the water shortage problem. The team have created a membrane able to purify water by simulating photosynthesis and the transpiration of plant leaves. The membrane consists of a double layer of nanoparticles, one of titanium dioxide (TiO₂) and the other of gold, on top of a support layer of anodized aluminum oxide.

During photosynthesis, the layer of TiO₂ absorbs light, breaking down toxic pollutants in the water, while the gold layer emulates the transpiration of a leaf and harnesses sunlight to evaporate the water at the surface. The resulting vapor condenses into completely-purified water.

In the first tests of the new system, 60% of a model pollutant was eliminated in just two hours of simulated sunlight. Such a result could well lead to new strategies and developments in harnessing solar energy and using it in water purification.

By simply imitating a natural process in an experiment, could we have found the solution to eradicating water shortages all across the globe?

 

Source: Science Daily