Synthesis And Properties Of Metal Sulfides Nanomaterials Based On The Single-Source Precursor Hydrothermal Method

Metal sulfide nanomaterials have been vastly studied for their unique chemical and physical properties,especially in the fields of photocatalysis,supercapacitors,bio-imaging,batteries,sensors and magnetism.The experiments were based on the reaction precursors synthesized by chemical precipitation at room temperature,and changed the experimental conditions such as adding different reaction solvents,different reaction time and the presence or absence of polyvinylpyrrolidone（PVP）surfactants to prepare a variety of morphologies of different metal sulfide nanomaterials.The properties of single-component metal sulfide nanomaterials in photocatalysis and adsorption were studied.At the same time,the metal sulfide and graphene composites were prepared and used as the electrode material of supercapacitor in the three electrode system.This paper include the following three parts:1.The comparison of the photocatalytic properties of CdS nanomaterials synthesized under different solventsWe used Cd（NO₃）₂·42O and C₅H₁₀NNaS2·3H₂O（sodium diethyldithiocarbam-ate）as the source of cadmium and sulfur,respectively,using PVP as the surface active agent,preparing a single source precursor by chemical precipitation method at room temperature.The CdS nanomaterials with different morphologies were prepared by putting a certain amount of precursors in ethylene glycol or ethylenediamine under high temperature and high pressure reaction conditions.The composition,structure,morphology,element valence and specific surface area of the synthesized samples were characterized by X-ray diffraction（XRD）,scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,X-ray photoelectron spectroscopy（XPS）and BET specific surface area.The photocatalytic degradation of Rhodamine B（RhB）was investigated by Xenon lamp.The results showed that CdS nanomaterials synthesized in different solvents exhibited different degradation characteristics in the catalytic degradation of RhB.The photocatalytic mechanism of different CdS nanomaterials was discussed and compared.2.Preparation of flower-like In₂S₃ nanomaterials by hydrothermal method and their adsorption and photocatalytic propertiesWe chosed In（NO₃）₃·xH₂O and C₅H₁₀NNaS2·3H₂O as a source of indium and sulfur source,respectively,without any surfactant,preparing a single source precursor by chemical precipitation method at room temperature.In₂S₃ nanomaterials were prepared by dispersing a certain amount of reaction precursors in a certain volume of water solvent under high temperature and high pressure reaction conditions.The different morphologies of the samples were obtained by different reaction time of the precursors at the same temperature,so the evolution of the flower morphology could be analyzed and deduced.XRD,TEM,SEM,XPS and UV-vis DRS were applied to characterize the composition,structure,morphology,element valence,and visible light absorption of the synthesized samples.The specific surface area of the In₂S₃ nanomaterials was 134.08 m2/g by BET specific surface area.Adsorption of methylene blue（MB）and photocatalytic experiments of methyl orange（MO）and antibiotic tetracycline（TC）onto In₂S₃ nanomaterials were studied.The results showed that the In₂S₃ nanostructures had a high adsorption-photocatalytic properties.The reasons for the high photocatalytic activity of this material was also analyzed and discussed.3.The NixSy/rGO composites were prepared by hydrothermal method and their electrochemical properties were studiedNi（NO₃）₂·4H₂O and C₅H₁₀NNaS2·3H₂O（sodium diethyldithiocarbamate）were used as nickel source and sulfur source,respectively.A single source precursor was prepared by chemical precipitation at room temperature without adding any surfactant.The composite of NixSy and reductive graphene was obtained by mixing the precursor with the graphene oxide solution under high temperature and high pressure reaction conditions.The morphology and composition of the samples were characterized by SEM and XRD.The results showed that the composite materials of nickel sulfide and redox graphene oxide could be prepared by this method.The effects of different cadmium and sulfur sources on the product composition were investigated.The electrochemical properties of NixSy/rGO composites were investigated in a three-electrode system.It was found that the product synthesized with the graphene was better than that of the NixSy product alone.It was also found that the single source precursor also had some capacitance properties.