Spherical Photocatalytic Materials Synthesis And Characterization Of Its Performance

In recent years,environmental pollution is becoming increasingly serious,which becomes a serious problem because of bringing a threat to human survival. Photocatalytic degradation of organic pollutions using semiconductor nanomaterials as catalysts becomes an effective method of pollution control,which becomes a hot issue of scientific research.ZnS,ZnO/TiO₂,CdS photocatalyst were synthesized via hydrothermal/solvothermal method.XRD,SEM and TEM were used to characterize the morphology and structure of the products,and the photocatalytic performance of the ZnS nanospheres and ZnO/TiO₂ composites was studied by decomposing methyl orange under UV light.Because of potential environmental problems of CdS nanoproducts,so the photovoltaic property of CdS microspheres was studied.The main results are as follows:(1) Zn(CH₃COO)₂·2H₂O and C₂H₅NS were utilized as starting materials to synthesize ZnS nanospheres ranging from 50 to 100 nm in diameter.This hydrothermal method with low energy consumption,which needs simple experimental conditions to generate a large quantity of ZnS products.Surfactant SDS is a key role to form ZnS nanospheres in this experiment.Compared to the bulk ZnS materials,ZnS nanospheres bring about 105nm blueshift.The photodegradation rate of methyl orange by ZnS nanospheres as catalysts reaches to 98%(2) The synthesis of ZnO/TiO₂ composites was carried out by a solvothermal method and ultrasonic precipitation followed by heat treatment.The photocatalytic performance of the synthetic products was studied by the degradation of methyl orange at different pH values.The best degradation rate was achieved at pH 2.0 in 60min.However,the degradation efficiency was the best at pH 11.0 before 30 min. HPLC-MS analysis showed that six intermediates were found during the photocatalytic degradation process of quinonoid MO.The degradation route of MO based mainly on hydroxylation and demethylation processes and the crucial C-N bonds breaking and sulfonic group removal.(3) CdCl₂ and C₂H₅NS were used as starting materials to produce 3D CdS cauliflower-like microspheres aggregated by nanoparticles ranging from 0.65 to 2.5μm in diameter.The present of surfactant SDS and the use of surfactant SDS amount are crucial to the formation of CdS cauliflower-like microspheres.3D CdS cauliflowers of two different crystalline structures were obtained by controlling the synthetic time.The photovoltaic results revealed that the hexagonal CdS microspheres have an advantage over the cubic CdS microspheres,however,the two samples of 3D CdS microspheres have an advantage over the CdS nanoparticles.