The Preparation And Safety Evaluation Of Molybdenum Sulfide Nanomaterials And Catalytic Performance Research

At present,with the rapid development of nanotechnology,nanomaterials have been widely penetrated into all aspects of life.Especially in recent years the new emerging two-dimensional layered transition metal nanomaterials(TMDs)have been widely concerned by researchers due to their large specific surface area,outstanding photothermal conversion efficiency and distinct catalytic activity.However,the extensive application of numerous nanomaterials would directly release into the natural environment or indirectly exposed to the ecological environment,which can consequently enter into living organisms and also cause potential hazards to human health.Therefore,on the one hand,this paper mainly focuses on design and preparation of MoS2 NSs and functional nano-reactors.On the other hand,the degradation,transport,transformation and safety of MoS2 NSs were studied by some novel methods,and the catalytic mechanism of functional nano-catalytic reactor was further studied.Firstly,we combined the advantages of synchrotron radiation(SR)X-ray absorption near-edge structure(XANES)and high-resolution single-cell SR transmission X-ray microscopy(SR-TXM)with traditional analytical techniques to investigate translocation,precise degraded species/ratio,and correlation between the degradation and toxicity levels of polyvinylpyrrolidone modified 2H-phase MoS2 nanosheets(MoS2-PVP NSs).These NSs demonstrated different biodegradability levels in biomicroenvironments with H2O2,catalase,and human myeloperoxidase(hMPO)(hMPO>catalase>H2O2)and their transport mechanism in single cell also been researched.Finally,MoS2-PVP NSs showed different accumulation and metabolic pathways after different administration methods.In addition,we have synthesized the 2H/1T mixed phase molybdenum disulfide nanosheets by one-step hydrothermal method.Then the MoS2-based nano-catalytic reactor with sequential catalytic performance was synthesized using by layer-by-layer self-assembly.We have demonstrated the self-assembly process by various characterization methods and found that not only the nano-catalytic reactor has good biocompatibility,but also in vitro catalytic experiments show that it has remarkable sequential catalytic capacity.Finally,the catalytic mechanism of MoS2-based nano-catalytic reactor was verified.