Researchers at TIFR develop new method to desalinate water

In a major scientific breakthrough in the field of water purification and sustainable engineering, a team of researchers from the Tata Institute of Fundamental Research (TIFR) led by Prof. Vivek Polshettiwar of the Department of Chemical Sciences has developed a new and improved method to desalinate water using gold nanoparticles and sunlight.

Why is this research significant?

• The work uses gold nanoparticles which can absorb sunlight over the entire visible region and also parts of the near-infrared light.
• This has enabled the researchers to use the nanoparticles to desalinate seawater using sunlight
• Seawater, while widely available, is not fit for drinking due to its high salt content.
• Conventional seawater desalination is energy intensive and that makes it more costly than other alternatives.
• The team was able to use natural sunlight to heat the water to 85 deg C which generated steam. This produced drinking water from seawater as about 10% of seawater evaporated to becomes steam (and thus becomes drinkable) in about 30 minutes.
• The formation of smaller gold nanoparticles (especially in the nanometer range 1-100 nm) allows variation in size, which is essential for harvesting light.
• The gold nanoparticles can also be used to convert carbon dioxide into methane. This would improve energy availability in the world.

Why is this work important for India?

Cities like Chennai which are near the sea coast are also suffering from lack of potable water. This makes seawater desalination a very attractive proposition for them. However, energy needs and costs are very high. With this type of technology, costs can be reduced and make cleaner water available for all.