Cyclic trinuclear unit derived porous aromatic framework for gold extraction from e-waste

Extracting gold from electronic equipment waste (e-waste) is a sustainable strategy for recycling precious metals, reducing environmental pollution, and meeting the growing demand for gold resources. In this work, we synthesized a porous aromatic framework (PAF-385) from cyclic trinuclear complex base building unit, which directly induce gold capture sites to the framework. The resulted gold capture PAF has significant gold extraction ability and high selectivity over other metals. The optimal adsorption capacity of PAF-385 for gold reaches 362 mg g-1. The adsorption process conforms to the pseudo second order kinetic model and Langmuir model, indicating that the adsorption of gold by PAF-385 is a monolayer adsorption on the surface of PAF-385 through chemical reactions. Regarding to its selectivity, PAF-385 shows about 8300 times higher selectivity for Au (III) than Pt (II). In addition, PAF-385 is capable of rapidly and effectively extracting gold from the central processing unit (CPU) under extremely acidic conditions, with a gold purity of 23.76 k (98.9% atomic ratio). PAF-385 provides a practical method for extracting gold from electronic waste due to its high acid resistance and anti-interference ability to inexpensive metals during the recycling process.