Recovery and in-situ reduction of precious metals by graphdiyne and graphdiyne oxide for antibacterial use

Based on the in-situ self-reduction and chemical stability, graphdiyne (GDY) and graphdiyne oxide (GDYO) are used as trapping agents to investigate the ability for recovering Au³⁺, Ag⁺, and Pd²⁺ under different pH values and interfering ions. Under strong acidity at pH = 1, these two agents demonstrate high select recovery towards the three precious metal ions, which could be in-situ reduced to nanoparticles (NPs). In addition, superparamagnetic Fe₃O₄ NPs are deposited on the surfaces of GDY and GDYO. The magnetic responses enable GDY-Fe₃O₄ to recover precious metals conveniently and efficiently by the aid of an external magnetic field. This study also confirms the antibacterial activity of the as-recovered NPs deposited on GDY and GDYO against Escherichia coli and Staphylococcus aureus (1 × 10⁵ colony-forming unit (CFU)·ml⁻¹), and the antibacterial rates are 100%. This strategy of recovering precious metals and subsequently reusing to combat pathogens will be of great significance for environmental remediation and biomedical applications.