Enhanced Catalytic Reduction of p-Nitrophenol on Ultrathin MoS₂ Nanosheets Decorated with Noble Metal Nanoparticles

In this work, ultrathin MoS 2 nanosheets (MoS 2 NSs) with defect-rich structure were prepared and used as catalysts for the reduction of p -nitropheonol. Also, thanks to the defect sites, noble metal (Au, Ag, Pd, Pt) nanoparticles (NPs) can be successfully deposited on the MoS 2 NSs via a facile and efficient one-step photochemical reduction process without the assistance of a stabilizer. The morphology and crystal structure of as-synthesized materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and N 2 physisorption mearurements. Catalytic results demonstrate that as-prepared MoS 2 NSs and noble metal modified MoS 2 NSs (NM/MoS 2 NSs) effectively catalyze the reduction of p -nitrophenol (p-NP) to p -aminophenol (p-AP) with NaBH 4 . The Pd/MoS 2 NSs shows the best catalytic performance, exhibiting an apparent rate constant (κ app ) of 0.386 min –1 even with moderate chemical stability. Interestingly, the activity of MoS 2 NSs is comparable to and even higher than previously studied noble metal-based catalysts. Moreover, the good reusability without significant activity loss suggests that MoS 2 NSs can be a strong candidate for sustainable chemical catalysis. The origins of the high catalytic activity are also discussed and a probable reaction mechanism is suggested. The present work opens up new opportunities for the future design and fabrications of versatile MoS 2 -based composite materials.