Highly efficient and selective gold mining with graphene oxide

Materials that can extract gold from complex sources, such as electronic waste (e-waste), are needed for sustainable gold supply and recycling. However, it remains difficult to achieve high profitability and precise selection when little gold is present next to the other metals.

This report describes a method based on specially treated graphene (rGO), a nanomaterial. It offers a very high yield and selective recovery of gold ions at very low concentrations (>1000 mg gold per gram of rGO at 1 ppm). The excellent performance is due to certain regions on the graphene and the properties of rGO.

These specific areas on the graphene reduce the gold ions to pure gold. Other properties of rGO ensure good dispersibility. Good dispersibility yields efficient uptake and reduction of gold ions in those areas. The scientists found a way to maintain control over certain parts of the rGO. This made it possible to extract gold exclusively, without being contaminated by the 14 other common elements in e-waste.

These findings show how gold can be recycled from real e-waste. It is a scalable and economically viable way, as demonstrated using rGO membranes in a continuous process.