Reduced graphene oxide (rGO) provides an ultrahigh capacity for the selective extraction of gold ions present in ppm concentrations (>1000 mg of gold per gram of rGO at 1 ppm). The excellent gold extraction performance is accounted to the graphene areas and oxidized regions of rGO. The graphene areas spontaneously reduce gold ions to metallic gold, and the oxidized regions allow good dispersibility of the rGO material so that efficient adsorption and reduction of gold ions at the graphene areas can be realized.
A group of scientists from Tsinghua University, Shenzhen Institute of Advanced Technology under the Chinese Academy of Sciences (CAS), Institute of Metal Research under the CAS, and the University of Manchester found that reduced graphene oxide material is highly capable of extracting trace amounts of gold from electronic waste. Gold is selectively extracted from electronic waste with no other coexisting metal elements, and without using additional energy and materials. The researchers also developed a gold adsorption method based on graphene films, which is suitable for large-scale production and can efficiently and continuously recover gold resources from electronic waste.