A US research team has developed a platinum and sulphur-based aerogel capable of purifying water and other contaminated solutions of toxic heavy metals, it has been reported.

The team from Northwestern University Illinois's "chalcogels" differ from standard aerogels by substituting oxygen for sulphur or selenium.

This enables them to absorb heavy metals such as lead and mercury far more efficiently than ever before, since these bind more preferentially with sulphur than with oxygen.

Tests on solutions showed 99.9 per cent of mercury was removed and 40 per cent of Zinc.

The breakthrough was enabled by the team's use of platinum in the process, which they found stabilised the solution and allowed the gel to form.

Mercouri Kanatzidis, who was involved in the project, told Chemistry World: "We wanted to use chalcogenide [sulphur or selenium containing] clusters but trying to form gels without using oxides often just gave us a precipitate instead.

"The secret was to use platinum to stabilise the structure, as well as slowing down the reaction to the point where the complex could form a network inside the liquid - giving rise to a gel."

The technology could also be used to remove heavy metals from products synthesised using heavy metal catalysts as well as in photocatalysis, Chemistry World reports.

Source:

Novel aerogels to absorb toxic heavy metals, 26/07/07
Platinum and suphur-based aerogel purfies heavy metals from water

Gel promises heavy metal clean-up, 26/07/07
http://news.bbc.co.uk/1/hi/sci/tech/6917753.stm


Ÿ Adfero Ltd