Synthesis And Characterization Of Different Dimensional Semiconduction Nanocomposites And Their Application In Catalysis Or Detection

Since the 1950s,nanotechnology has been developed rapidly in recent years,nanomaterials had been expanded to application in differet fields like the chemical,physical,medical and other fields because of their unique features that include small size,high surface and so on.Among them,semiconductor nanomaterials can be used for photocatalysis and spectroscopic detection because of light and photoelectric properties.Thence,based on the previous research of previous results,this paper synthesized different dimensional semiconduction nanocomposites and their application in catalysis or detection:i.constructing two-dimensional CuFeSe₂@Au heterostructured nanosheets with an amorphous core and a crystalline shell for enhanced near-infrared light water oxidation;ii.porous CuFeSe₂/Au heterostructured nanospheres-based dual-functional SERS sensor for ultrasensitive detection of lung cancer cells and their biomarkers;ii.large-scale synthesis of leaf-shape Zn_0.6Cd_0.4S nanosheets utilizing ZIF-L template for highly efficient visible-light-driven hydrogen generationThe thesis is divided into four chapters,stated as follows:Chapter 1:First,we summarize the field of nano-materials science and technology including the development of nanotechnology and the classification of nanomaterials.Then the synthesis methods and applications of different dimensions of nanomaterials are described.Finally,the application of nanometer materials in the fields of photolysis and Raman detection is introduced.Chapter 2:In this paper,this thesis first reported constructing two-dimensional CuFeSe₂@Au heterostructured nanosheets with an amorphous core and a crystalline shell by reducing Au³⁺ions to Au⁰on the surface of CuFeSe₂ frameworks under NIR irradiation.The as-prepared CuFeSe₂@Au heterostructured nanosheets has a wide wavelength absorption range?800-1800 nm?,which can be used in the photocatalytic water oxidation reaction under the NIR light irradiation?>850 nm?.This work provides a new idea for the synthesis of a new type of two-dimensional nuclear shell semiconductor metal heterostructure with enhanced near-infrared photocatalysis.Chapter 3:in this paper,we demonstrated a novel kind of hierarchical porous CuFeSe₂/Au heterostructured nanospheres for specific and sensitive detection of lung cancer biomarkers of aldehydes and lung cancer cells.The heterostructured nanospheres were constructed by loading an Au shell formed by photoreduction on the CuFeSe₂ frameworks.P-aminothiophenol?4-ATP?as Raman-active probe molecule was first grafted on CuFeSe₂/Au nanospheres,and then the gaseous aldehyde molecules were sensitively captured onto the nanospheres by the nucleophilic addition reaction,with the detection limits of the ppb?parts per billion?level.Moreover,the resulting folic acid?FA?-conjugated nanospheres present a high SERS activity to Rhodamine B isothiocyanate?RBITC?,which can be used to specifically recognize and sensitively detect the A549 cells.Our study suggested that the synthesized CuFeSe₂/Au heterostructured nanospheres as a multimodal platform could find a wide range of application in the field of medicine,biotechnology and environmental sciences.Chapter 4:in this paper,we synthesized large-scale leaf-shape Zn_0.6Cd_0.4S nanosheets utilizing ZIF-L template.The as-prepared Zn_0.6Cd_0.4S nanosheets have high specific surface areas,abundant active sites,chemical stability and exotic electronic properties,which suggest their promise for use in applications in the field for highly efficient visible-light-driven hydrogen generation.Therefore,the method of synthesizing Zn_0.6Cd_0.4S nanosheets has played an positive influence in guiding the synthesis of other types of semiconductors.