Preparation And Properties Of Dual Metal Sulfides Nanomaterials

As an important kind of semiconductor materials,metal sulfide nanoparticles with the special unique photoelectric effect,hold great potential applications in the field of optical absorption,photoelectric conversion,nonlinear optics,photocatalysis and sensors.One dimension nanowires have attracted wide attention due to their large specific surface areas,more active sites,and the advantage to the axial transfer of electrons.In this thesis,one dimensional CuS nanowires and CuS/ZnS hetero-nanowires were synthesized and characterized,and the photocatalytic properties of the products were measured.Besides,CuS/rGO was synthesized by in situ growth method and property of the microwave absorbing was measured.The details are as follows:?1?CuS nanospheres,CuS nanowires and CuS microsphercial-flowers were synthesized by one pot solvothermal method,with Cu?CH₃COO?₂·H₂O,Cu?NO₃?₂·3H₂O and CuCl₂·2H₂O as the copper sources respectively,and thiourea as the sulfur source.Their photocatalytic activities of products for degradation of methylene blue were tested.As-prepared CuS nanowires exhibited photocatalytic efficiency of 97%in 60 min.It showed much better photocatalytic activity than CuS microsphercial-flowers and CuS nanospheres.?2?Novel hierarchical CuS/ZnS hetero-nanowires were designed and successfully synthesized through a template-free and surfactant-free chemical solution method.The precursors of CuS,temperature and the molar ratio of Cu:Zn,played a crucial role in controlling the morphology of the CuS/ZnS heterostructure.The as-prepared samples were examined by X-ray diffraction,X-ray photoelectron spectroscopy,scanning electron microscopy,transmission electron microscopy,UV-visible diffuse reflectance spectrum and Brunauer-Emmett-Teller measurement.Photocatalytic activities of hierarchical CuS/ZnS hetero-nanowires for methylene blue and rhodamine B were investigated under visible-light irradiation and appreciably increased photocatalytic activity was achieved.The photocatalytic reactions were conducted in the presence of quenchers of photo-generated electrons,holes,and reactive oxygen species,which proved the electron was the most active species,and the possible degradation mechanism was proposed.The P-N heterojunction,one-dimensional nanostructures and large specific surface area are responsible for the improved photocatalytic activities.The shell structure of ZnS can effectively restrain the photocorrosion of CuS.?3?Graphite oxide was successfully prepared by modifying the Hummers method,and based on this,CuS/rGO compound was synthesized by one pot method.The structure and morphology of the product was characterized by XRD,SEM and TEM,which confirmed the loading of CuS on rGO,and it was found that the introduction of graphene limited the aggregation of CuS nanowires.The content of rGO in CuS/rGO was measured as 10%by thermogravimetric analysis.The microwave absorbing properties of CuS/rGO was better than that of CuS.when the thickness of the absorbent was 4 mm,CuS/rGO showed the strongest absorption for-13.6 dB,in 4.91 GHz,effective frequency width?RL<-10 dB?is 1.4 GHz.