Fe₃O₄@MoS₂ Core–Shell Composites: Preparation, Characterization, and Catalytic Application

Molybdenum disulfide (MoS₂) has received tremendous attention due to the earth-abundant composition and high catalytic activity. However, the catalytic activity of MoS₂ except electro- and photocatalytic has seldom been explored. Herein, Fe₃O₄@MoS₂ core–shell composites were prepared for the first time by <i>in situ</i> growth of MoS₂ nanosheets on the surfaces of Fe₃O₄ nanoparticles under different temperature, and the catalytic performance of the resulting composites was evaluated by using the catalytic reduction of 4-nitrophenol to 4-aminophenol. FE-SEM, TEM, XRD, and XPS analyses verified the core–shell structure with MoS₂ nanosheets of defect-rich and oxygen incorporation on the surfaces of Fe₃O₄ nanoparticles. Fe₃O₄@MoS₂ composites were found to exhibit a high catalytic activity for the reduction of 4-nitrophenol with the highest activity factor <i>k</i> = 3773 min^–1 g^–1. A plausible catalytic mechanism for the reduction of 4-nitrophenol was also proposed. This study presents an inexpensive, reusable, fast, and highly efficient catalyst for the reduction of 4-nitrophenol without noble metals