Photo-Enhanced Precious Metal Recovery Enabled by Trithiocyanuric-Linked Covalent Triazine Frameworks

Abstract

Precious metals recovery from secondary resources is crucial for ensuring the sustainable supply of resources and development of circular economy. Herein, the trithiocyanuric-linked covalent triazine frameworks (denoted as TTC-CTFs) are proposed and constructed for efficient recovery of precious metals. As expected, the proposed TTC-CTFs afford ultrahigh uptake capacities of 3365 mg g−1 for Au(III) and 1125 mg g−1 for Pt(IV) under light irradiation, achieving the respective 2.3-fold and 1.5-fold enhancement relative to those in the dark and outperforming the previously reported materials. Meanwhile, the recovery process possesses fast kinetics and superior recyclability, as reflecting by 15 min of the equilibrium time and neglect decline in recovery efficiency during ten cycles, respectively. Post-recovery characterizations and theoretical calculations reveal the combination of adsorption, photoreduction/chemical reduction, and crystallization is responsible for the photo-enhanced Au recovery. Significantly, TTC-CTFs are also competent for selective and efficient gold recovery from the computer processing unit (CPU) leachate, as companied by 99% of recovery efficiency and considerable profit, highlighting the feasibility of the proposed TTC-CTFs for the precious metal recovery from the actual e-waste.

Keywords: TTC-CTFs, precious metals, recovery, photo-enhanced, Reduction