Controllable Preparation Of Copper Oxide And Tin Dioxide Micro-nano Materials And Their Photocatalytic Properties

Micro-nano materials because of its unique physical and chemical properties in catalysis,sensing,optoelectronics has a wide range of applications,Therefore,preparation of novel metal oxide nanomaterials,controlling their morphology,size and dimension,and studying their growth mechanisms have become the hot topics in this field.In this dissertation,novel CuO micro-nano materials and SnO2 micro-nano materials were prepared by using micro-nano materials of semiconductor metal oxides(CuO and SnO2)and discussed its possible formation mechanism.The application of these four kinds of micro-nano materials as photocatalysts to degrade organic pollutants was studied.(1)A novel three-dimensional octagonal-like CuO nanostructure with a diameter of 10-15 ?m was successfully prepared by hydrogen peroxide-assisted hydrothermal-calcination method.By changing the amount of hydrogen peroxide(H2O2)can change the shape of the product.The octagonal-like CuO nanostructures showed more excellent degradation effect than the commercial CuO and other reported CuO products by photocatalytic degradation of Rhodamine B aqueous solution under visible light irradiation with the prepared octagonal-like CuO nanostructures as a photocatalyst.Finally,we analyzed the advantages of this structure in photocatalytic degradation.(2)The pumpkin-like porous CuO nanostructures were prepared with environmental protection reagents.The nanostructures have an average particle size of about 1-2 ?m.According to the test and characterization,the mechanism of self-assembly nucleation and growth of the product was put forward,and the role of the surfactant in the reaction was tested and analyzed.Finally,the prepared pumpkin-like porous CuO nanostructures were studied under UV light irradiation and found that they can degrade RhB solution well and have excellent stability and repeatability.(3)A novel hierarchical flower-like SnO2(HFL-SnO2)nanostructures were successfully synthesized by hydrothermal method.It has been found that the hierarchical nanostructure of SnO2 is formed by the cross-linking and assembly of many regular nanosheets in the flower-like structure.The material has a high specific surface area of 78.8 m2 g-1.Based on the nucleation and self-assembly process and a series of experiments with time axis,a reasonable growth mechanism of the product is proposed.We further investigated the effect of the amount of SDS and NaCl added on the nanostructures.Finally,the photocatalytic performance of the product was tested,and the photocatalytic degradation of RhB aqueous solution under visible light was excellent.The degradation rate was 93.6%within 120 min.(4)We have successfully prepared a novel layered dahlia-like SnO2 nanostructures using a simple hydrothermal method.During aggregation,nucleation and self-assembly,no template or surfactant was used and only the laminar flower-like structure was formed with NaCl as the crystal growth regulator.The synthesized product has excellent photocatalytic degradation effect on MO,and the degradation rate within 120 min is 87.4%,which is much higher than that of other reported SnO2 nanostructures under visible light irradiation.Finally,according to the test and characterization,the nanostructures are discussed in detail as a reasonable growth mechanism with reaction time as the axis.