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

In this work, ultrathin MoS2 nanosheets (MoS2 NSs) with defect-rich structure were prepared and used as 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 MoS2 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 MoS2 NSs and noble metal modified MoS2 NSs (NM/MoS2 NSs) effectively catalyze the reduction of p-nitrophenol (p-NP) to p-aminophenol (p-AP) with NaBH4. The Pd/MoS2 NSs shows the best catalytic performance, exhibiting an apparent rate constant (K-app) of 0.386 min(-1) even with moderate chemical stability. Interestingly, the activity of MoS2 NSs is comparable to and even higher than previously studied noble metal-based catalysts. Moreover, the good reusability without significant activity loss suggests that MoS2 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 MoS2 based composite materials.