Published in the Royal Society of Chemistry journal Nanoscale: New Monash University research has found a simple and effective way of capturing graphenes and the toxins and contaminants they attract from water by using light. The findings could have significant implications for large-scale water purification.
The research demonstrates that small amounts of a special light-sensitive soap, which is added to water containing graphenes and contaminants, changes its molecular structure when light of a particular colour shines onto it. This changes the way it interacts with carbon materials in the graphene and causes them to separate out (along with contaminants stuck to them), enabling easier extraction of the graphenes and contaminants. Shining a different coloured light re-disperses the graphenes for re-use.
According to co-author Dr Rico Tabor from Monash, graphenes are extremely promising for the purpose of water purification.
This is because the structure is essentially two-dimensional and only an atom thick. Graphene `sheets' have therefore the highest surface area possible, meaning their capacity to mop up contaminants in water surpass that of any currently used materials or membranes.
But traditional approaches for the extraction of graphene and contaminants from water either require centrifugation, which uses high amounts of energy, or the addition of large amounts of polymer at high cost.
The new technology offers a better and cheaper alternative, as light is abundantly available, simple and low cost, as co-author Thomas McCoy pointed out.
