Magnetic Co-Doped MoS Nanosheets for Efficient Catalysis of Nitroarene Reduction.

Co-doped MoS nanosheets have been synthesized through the hydrothermal reaction of ammonium tetrathiomolybdate and hydrazine in the presence of cobalt acetate. These nanosheets exhibit a dominant metallic 1T phase with cobalt ion-activated defective basal planes and S-edges. In addition, the nanosheets are dispersible in polar solvents like water and methanol. With increased active sites, Co-doped MoS nanosheets exhibit exceptional catalytic activity in the reduction of nitroarenes by NaBH with impressive turnover frequencies of 8.4, 3.2, and 20.2 min for 4-nitrophenol, 4-nitroaniline, and nitrobenzene, respectively. The catalyst is magnetic, enabling its easy separation from the reaction mixture, thus making its recycling and reusability simple and efficient. The enhanced catalytic activity of the Co-doped 1T MoS nanosheets in comparison to that of undoped 1T MoS nanosheets suggests that incorporation of cobalt ions in the MoS lattice is the major reason for the efficiency of the catalyst. The dopant, Co, plays a dual role. In addition to providing active sites where electron transfer is assisted through redox cycling, it renders the nanosheets magnetic, enabling their easy removal from the reaction mixture.