Cyanide-functionalized ionic liquid-modified polymer as an adsorbent for highly efficient and selective recovery of Au(III)

Designing and synthesizing sustainable adsorbents for the separation and recovery of gold from waste resources has significant importance to alleviate the problems of the scarcity of resource and environmental pollution. Herein, a cyanide-functionalized ionic liquid-modified polymer (CPR-CN) was prepared by a simple one-step process for gold (Au(III)) recovery. The introduction of cyan group and cationic imidazolium ring gives CPR-CN significant adsorption ability with 1450.41 mg/g. Kinetics study suggested that the uptake of Au(III) onto CPR-CN could be commendably matched by the pseudo-second order kinetic model and it took only 10 min to reach adsorption equilibrium. The CPR-CN had a remarkable selectivity towards Au(III) for it presented much overwhelming affinity for Au(III) than that for other base metal ions such as K(I), Co(II), Cu(II), Ca(II), Mg(II), Al(III) and Fe(III), thus it was successfully applied to recover Au(III) from e-waste leaching solution. Besides, the CPR-CN displayed preferable reusability, and the possible mechanism of CPR-CN for Au(III) was investigated with the aid of several characterization techniques. These performance of CPR-CN indicates it can serve as an attractive adsorbent to efficiently and selectively separate and recover Au(III) from waste.