Gold itself doesn't directly purify water in the traditional sense of filtering out physical impurities. Instead, gold nanoparticles, when coated with a metal-organic framework (MOF), facilitate a chemical reaction driven by sunlight to break down harmful contaminants. This process is called photocatalysis.
Here's a breakdown:
- The Role of Gold: Gold nanoparticles act as a catalyst. They enhance the reaction speed without being consumed in the process.
- Metal-Organic Framework (MOF): The gold nanoparticles are coated with a MOF. This coating helps to improve the gold's interaction with sunlight.
- Photocatalysis: When exposed to sunlight, the gold-MOF combination initiates photocatalysis. This process involves the gold reacting with sunlight to oxidize contaminants, effectively breaking them down.
- Contaminant Removal: Specifically, this photocatalytic reaction can break down microcystins, which are toxins produced by cyanobacteria (blue-green algae) and can be harmful in drinking water. The oxidation process transforms these toxins into less harmful substances.
In summary, gold doesn't purify water by physically removing particles, but by acting as a catalyst in a reaction powered by sunlight that breaks down harmful contaminants at a molecular level.
