Selective recovery of gold ions in aqueous solutions by a novel trithiocyanuric-Zr based MOFs adsorbent

A trithiocyanuric-Zr based MOFs adsorbent (ZT-MOFs) was synthesized by using trithiocyanuric acid as a linker and zirconium chloride as a metal matrix and used to recover Au(III). ZT-MOFs was characterized by FT-IR, BET, Raman and FE-SEM. ZT-MOFs are porous material and have good stability in the range of pH 1–9. ZT-MOFs showed a higher adsorption capacity for Au(III) (333.34 mg/g) at 480 min and pH = 7. The experimental data fitted to Freundlich and pseudo second-order models, indicating a heterogeneous multi-layer chemadsorption is the dominated step. ZT-MOFs separated selectively Au(III) from laboratory wastewater containing various interfering ions. The removal rate of Au(III) decreased only from 94.5% to 87.5% after 4 adsorption and desorption cycles. This shows that ZT-MOFs have good repeatability. FT-IR, XPS and Zeta potential data shows that the adsorption mechanism of Au(III) on ZT-MOFs is coordination. Therefore, ZT-MOFs have great potential in extracting Au(III) from wastewater.