Efficient adsorption of Au(III) from acidic solution by a novel N, S-containing metal–organic framework

Due to the special status of precious metals in the preparation of high-tech materials, the recycling of precious metals has important practical significance. A novel metal–organic framework called as Zn-AMT containing large number of functional atoms (N, S) was prepared as a highly efficient adsorbent to recover Au(III) from acid solution. Compared with the reported adsorbents, Zn-AMT shows remarkable adsorption efficiency towards Au(III) with the maximum adsorption capacity up to 2040 mg·g−1 at 25 °C. Increasing temperature to 42 °C could make the adsorption capacity increased to 2878 mg·g−1. The adsorption ratio of 100% could be achieved for the low Au(III) concentration within 100 mg·L-1. The Zn-AMT shows both excellent selectivity and good reusability. The adsorption kinetics data follow the pseudo-second-order kinetics and the adsorption isotherms data are well fitted by the Langmuir model. The adsorption mechanism was deduced that the Au(III) was firstly adsorbed onto the surface of Zn-AMT through electronic attraction and the coordination interaction of -SH, and then in situ reduced to Au(I). With the prominent adsorption performance, excellent selectivity, and admirable reusability, the Zn-AMT adsorbent could be a promising candidate for gold recovery in practical application.