Performance and Mechanism of Hydrothermally Synthesized MoS2 on Copper Dissolution

The recovery of copper from circuit boards is currently a hot topic. However, recycling copper from circuit boards economically and environmentally is still a considerable challenge. In this study, a simple hydrothermal method was used to synthesize MoS2 with nano-flower-like morphology using sodium molybdate dihydrate and thiourea as molybdenum and sulfur sources. The metal copper in the chip was successfully dissolved under the action of free radicals produced by ultrasound. The results show that under the catalytic action of hydrothermal synthesis MoS2, the concentration of Cu2+ dissolved by ultrasonic treatment for 10 h is 39.46 mg/L. In contrast, the concentration of Cu2+ dissolved by commercial MoS2 is only 2.20 mg/L under the same condition. The MoS2 is polarized by external mechanical forces and reacts with water to produce H+ and free electrons e−, which can combine with O2 and OH− to produce ·OH and ·O2− free radicals. Elemental Cu is converted to Cu2+ by the attack of these two free radicals.