Synthesis And Photocatalytic Properties Study Of Metal Sufild Nanostructures

In recent years, as a green technology, semiconductor photocatalysis hasreceived a great deal of interest due to its universal applications in utilization of solarenergy, environmental purification, and degradation of organic to CO2and H2O.Among the plentiful photocatalysts, due to its high photocatalytic activity physicaland chemical stability, nontoxcity, low cost and easy availability, titanium oxide （TiO2）always has been regarded as one of the most promising photocatalysts in practicalapplications. However, the low quantum efficiency of photocatalytic reactions and theineffective utilization of visible light or sunlight for TiO2, which result from the wideband gap（3.2eV）requiring ultraviolet irradiation to activate it, impair its applicationsto great extent. Therefore, exploring photocatalysis with visible light activity has beenthe subject of numerous studies. Consequently, Transition metal sulfides have attractmuch attention as one of the strongest candidate photocatalysts due to their desirableband gap, easy availability and controllable morphology.Flower-like copper monosulfde （CuS） hierarchical nanostructures composed ofnanoplates were successfully synthesized by a simple solvothermal process. Themorphology and structure of the product were characterized by X-ray powderdiffraction （XRD）, scanning electron microscopy （SEM）, and transmission electronmicroscopy （TEM）.The optical properties of the copper monosulfde hierarchicalnanostructures were investigated by UV-visible absorption spectra. In addition, thephotocatalytic activity of the flower-like CuS hierarchical nanostructures has beenevaluated by the degradation of methyl orange solution under natural light. Theresults demonstrate that the as-prepared flower-like CuS hierarchical nanostructurespossesses high photocatalytic performance, the degradation rate is up to100%after90min degradation under the irradiation of natural light, which is much higher thanbulk CuS powder. The plausible forming mechanism of flower-like CuS hierarchicalnanostructures has been proposed and the effect of reaction time，the solvent andS-source on morphology has been discussed.Flower-like bismuth sulfide （Bi₂S₃） hierarchical nanostructures and bismuthsulfide nanorods were successfully synthesized via a simple hydrothermal route. Thecomposition, morphology, and structure of the products were characterized by XRD,SEM, EDX and TEM. The optical properties of the bismuth sulfide nanocrystals were investigated by UV-visible absorption spectra. The photocatalytic activity of theproduct has been evaluated by the degradation of rhodamine B solution underultraviolet light and visible light. The results demonstrate that the product possessesgood optical quality and catalytic performance. The photocatalytic activity o f theBi₂S₃hierarchical nanostructures is much better than Bi₂S₃nanorods.The degradationrate of rhodamine B is up to96.4%and78.3%after90min degradation under theirradiation of high-pressure mercury lamp and sunlight, respectively. The formingmechanism of flowerlike Bi₂S₃hierarchical nanostructures were preliminarilyanalysised.It was revealed that the surfactant have great influence on the morphologyand size of the resulting Bi₂S₃products.