Efficient recovery of precious metal based on Au–S bond and electrostatic interaction

A water soluble thiourea-modified polyethylenimine copolymer was synthesized and utilized as a precious metal recovery material with high efficiency (16.0 mmolAu gpolymer−1). The recovery mechanism was clearly revealed, and the Au–S bond between thiourea and AuIII and the electrostatic interaction between amino groups and AuCl4− were involved.