Preparation And Properties Of Cu-based Composite Semiconductor Nanomaterials

With the development and progress of nanometer science and technology,high efficiency,energy saving,environmental protection and practical nanomaterials synthesis technology have become the subject of scientific research.Compared with traditional bulk semiconductor materials,metal oxides and metal-oxide semiconductor nanomaterials have unique photoelectric conversion characteristics,gas sensing properties and photocatalytic properties.It has more surface active sites,smaller particle size and larger specific surface area than traditional bulk semiconductor nanomaterials.At the same time,during the preparation of semiconductor nanomaterials,the properties of the samples will be greatly affected because of the difference between the morphology and structure of the samples.Therefore,combining the excellent oxides with other compounds or precious metal elements to form a heterojunction can not only increase the performance of the original structure,but also fully maximize the utilization of the original resources.At present,the preparation of nanomaterials is more inclined to use other compounds or precious metal modification to obtain core-shell structure or heterojunction structure,which can effectively control the combination of electron and hole pairs in semiconductor,thus improving its catalytic efficiency.In this paper,copper oxide nanomaterials with different morphologies were synthesized rapidly and efficiently by solvothermal method,and Cu₂O was used as template.The semiconductor core-shell structure nanomaterials such as Au-Cu₂O,Ag-Cu₂O semiconductors nanomaterials were synthesized by the modified synthesis of noble metals,and other sulfur compounds were used to synthesize Cu₂0-Cu_2-XY?S/Se/Te?semiconductor nanomaterials.The structure and morphology of composite semiconductor nanomaterials with different compositions were characterized and the formation mechanism of the products was preliminarily discussed.The main contents of this thesis are as follows:The homogeneous morphologies of cuprous oxide cubes,microspheres,hollow spheres and nuclear shell structures were prepared by polyol reduction method.The effects of copper sources,reaction time,polyol types and active agents?PVP?on the morphology of cuprous oxide micro nanomaterials were also investigated.The formation mechanism of the products was preliminarily discussed.The strongest absorption peak of the cuprous oxide nanospheres is about 500nm.However,the peak absorption peak of cuprous oxide is about 300nm,and a wider absorption peak is around450nm,and the next step is to prepare the cuprous oxide base with high catalytic activity for the next step.The conductor composite provides an important reference value.Gold and silver modified cuprous oxide core-shell structure and heterojunction composite semiconductor nanomaterials were rapidly synthesized at 180°C by polyol reduction method.The catalytic reduction of 4-nitrophenol by composite semiconductor nanomaterials composed of Au/Ag-Cu₂O was preliminarily investigated.The results show that 4-nitrophenol can be reduced at room temperature and temperature to 40°C.at room temperature,all the catalysts with the same concentration can completely catalyze the reduction of 4-nitrophenol after 10min or 10min.However,when the temperature rises to 40°C,the catalytic properties of Au-Cu₂O?Cu₂O-Au?Ag-Cu₂O and Cu₂O-Ag in the composite semiconductor nanomaterials are improved,and Au-Cu₂O reaches its strongest catalytic performance at 40°C,and the 4-nitrophenol with 0.12mmol·L^-1 can be rapidly reduced in 3 minutes.Cu₂O-Cu_2-XY?S/Se/Te?core-shell composite nanomaterials were prepared by a simple solvothermal method using cuprous oxide nanostructures as templates.The hollow structure Cu_7.2S₄,CuSe and Cu₂O-Cu_2-xY?Y=S,Se,Te?composite semiconductor nanomaterials with different components were successfully prepared by reacting with VIA family compounds at a constant temperature.The results show that the homogeneous Cu_7.2S₄,CuSe and Cu₂O-Cu_2-xY?Y=S,Se,Te?cube structures can be obtained by excessive VIA family compounds.The results show that the structure of the hollow cube can be obtained.The solid-state UV-Vis/NIR absorption spectra show that there is a strong absorption in the visible light and near infrared light,and the absorption peak in the near infrared region increases with the increase of the molar amount of Y?Y=S,Se,Te?source.