Now, a simple answer to clean water!

Press Trust Of India

Washington, June 09, 2010

In what could make the treatment of waster water easier, scientists have shown that a simple inorganic compound and sunlight can help oxidise water, by breaking down contaminants.

An international team has demonstrated that silver orthophosphate can efficiently be used to oxidise water with only the power of light -- in fact, the oxidisation process can be used to convert solar energy to clean energy or break down contaminants in water, the 'Nature Materials' reported.

"With increasing worldwide interest in alternative renewable sources of energy, as well as on the need to clean up environmental pollution, developing materials that can be used to efficiently convert solar energy to clean energy or to decompose organic contaminants is a vitally important task," said team leader Zhiguo Yi of Australian National University.

Added team member Prof Ray L Withers: "The material we have studied is a very simple inorganic semiconductor - silver orthophosphate. Under visible light illumination this material shows an amazing ability to oxidise water to release oxygen as well as to break down organic contaminants such as methlyene blue, Rhodamine B and other chemicals which may be undesirable in water supplies.

"Our work here, however, has uncovered that silver orthophosphate can be regenerated in an energy-efficient manner by an electrochemical method."

According to the scientists, the next step will be to look at the use of electricity to power the process.

"We are optimistic about future uses of silver orthophosphate, although there remain problems to overcome as electrical energy is still required to generate hydrogen and for the material to regenerate itself. However, the results are important and encouraging first step towards solving energy and environmental issues," said Dr Yi.