Huang Hui, Xiong Huihui, Gan Lei
School of Metallurgy Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China.
Molecules. 2023 Nov 2;28(21):7390. doi: 10.3390/molecules28217390.
The technique of gold collection in matte can effectively improve the trapping efficiency of precious metals such as gold, silver, and platinum. However, the underlying mechanism of gold collection from high-temperature molten matte is complex and not well understood. In this work, the first-principle calculations were utilized to investigate the adsorption behavior of gold atoms on a CuS surface. The effects of vacancies and As and Sb doping on the gold-trapping ability of CuS were also explored, and the electronic properties of each adsorption system, including the charge density difference, density of states, and charge transfer, were systematically analyzed. The results show that the Cu-terminated CuS(111) surface has the lowest surface energy, and the Au atom is chemically adsorbed on the CuS(111) with an adsorption energy of -1.99 eV. The large adsorption strength is primarily ascribed to the strong hybridizations between Au-5d and Cu-3d orbitals. Additionally, the Cu vacancy can significantly weaken the adsorption strength of CuS(111) towards Au atoms, while the S vacancy can notably enhance it. Moreover, due to the formation of strong covalent As-Au/Sb-Au bonds, doping As and Sb into CuS(111) can enhance the gold-trapping capability of CuS, and the Sb doping exhibits superior effectiveness. Our studied results can provide theoretical guidance for improving the gold collection efficiency of CuS.
冰铜中金的捕集技术能够有效提高金、银、铂等贵金属的捕集效率。然而，高温熔融冰铜中金的捕集潜在机制复杂，尚未得到充分理解。在本工作中，利用第一性原理计算研究了金原子在硫化铜表面的吸附行为。还探究了空位以及砷和锑掺杂对硫化铜捕金能力的影响，并系统分析了各吸附体系的电子性质，包括电荷密度差、态密度和电荷转移。结果表明，铜端终止的硫化铜（111）表面具有最低的表面能，金原子以-1.99 eV的吸附能化学吸附在硫化铜（111）上。较大的吸附强度主要归因于金5d与铜3d轨道之间的强杂化作用。此外，铜空位会显著削弱硫化铜（111）对金原子的吸附强度，而硫空位则会显著增强该吸附强度。而且，由于形成了强共价键砷-金/锑-金键，将砷和锑掺杂到硫化铜（111）中能够增强硫化铜的捕金能力，且锑掺杂表现出更优异的效果。我们所研究的结果可为提高硫化铜的金捕集效率提供理论指导。
