Rapid extraction of gold from complex solutions by metal sulfides

Abstract

The industrial application potential of current adsorbents for Au(III) recovery is limited due to their high costs, poor adsorption capacity, and complicated preparation processes. This study introduces a novel approach to address these challenges by synthesizing metal sulfides through a one-step hydrothermal method. The synthesized metal sulfides exhibit exceptional adsorption capacities, exceeding 1500 mg/g. Particularly, petal-shaped CuS demonstrates outstanding performance in extracting gold from complex solutions, including fresh water and simulated leaching liquid of electronic circuit boards. With an impressive adsorption capacity of 2536 mg/g in a 700 mg/L Au (III) spiked solution, CuS achieves a remarkable 90.6% removal efficiency. The adsorption process of CuS on gold can be well described by a pseudo-second-order kinetic model and the Langmuir model. Furthermore, CuS is successfully loaded onto sodium alginate (SA) aerogel for large-scale applications. The layered structure of SA overcomes the challenge of solution retrieval, making it a promising material with outstanding removal performance for industrial use. In cases where a high specific surface area does not confer advantages, CuS demonstrates superior performance compared to numerous gold ion adsorbents. This observation motivates us to emphasize the content of active functional groups during the design of gold ion adsorbents. This research significantly advances the field of Au(III) recovery by providing cost-effective and efficient adsorbents with simplified synthesis processes and strong adsorption capabilities.