Abstract

MoS2 materials performed well as adsorbent for Au(S2O3)23- recovery, but the effect of its crystal facets on recovery behavior and mechanism remained unclear. In this study, flower-shaped MoS2 with exposed (110) facet and flake-shaped MoS2 with (002) exposed facet have been synthesized through a simple hydrothermal method, and their recovery performance and mechanism for gold from Au(S2O3)23- solution were explored. The results indicated that MoS2 materials could recover Au(S2O3)23- via adsorption and photocatalytic reduction. Importantly, MoS2 materials with different exposed facets displayed crystal anisotropy, which greatly affected the recovery behavior of Au(S2O3)23-. Flake-shaped MoS2 showed better dispersibility because of stronger surface electronegativity, and flower-shaped MoS2 displayed better photocatalysis property thanks to more activated edge sites. The better dispersibility made flake-shaped MoS2 have higher contact probability to Au(S2O3)23- molecules, resulting in faster recovery rate as well as higher recovery for Au(S2O3)23- with low concentration. Meanwhile, flower-shaped MoS2 with better photocatalysis property could release more photogenerated electrons, so that achieving more excellent recovery for Au(S2O3)23- with high concentration. The finding in this study enhanced the understanding about the effect of MoS2 facets on Au(S2O3)23- recovery, which had great significance for the design of MoS2 structure and green production of gold in the future.