Preparation, Characterization And Properties Of Copper Selenide And Copper Oxide Micro/Nanomaterials

Copper selenide and copper oxide micro/nanomaterials have attracted much research interest due to their excellent properties in sensors,electrocatalysis,photocatalysis,photovoltaic devices,lithium ion batteries,and antibacterial agents etc.In this thesis,Cu₃Se₂/Cu₂Se/Cu₂O composite hollow microspheres,candy-like Cu₄O₃ and ball-flower-like CuO micro/nanomaterials were prepared by a facile wet chemical method.The products were characterized by XRD,SEM,TEM,XPS,TG-DTA and UV-vis diffuse reflectance absorption spectra.The influences of reaction conditions on the morphologies and structures of the products were investigated by series of controlled experiments,and the formation mechanisms were proposed.The photodegradation activities to organic dye solutions of methyl blue,methylene blue,rhodamine B and methyl orange,and the antibacterial activities against Staphylococcus aureus?S.aureus?and Escherichia?E.coli?coli were studied.The main content of this thesis includes:1.Cu₃Se₂/Cu₂Se/Cu₂O composite hollow microspheres with Cu₃Se₂ as the main component have been synthesized successfully by a facile sacrificial template method,using Cu₂O microspheres as the template.The Cu₃Se₂/Cu₂Se/Cu₂O product was characterized by XRD,SEM,TEM,XPS,UV-vis diffuse reflectance absorption spectrum and photoluminescence?PL?spectrum and its formation mechanism was explored based on series of control experiments.The photocatalytic activities were assessed by photodegradations of three organic dye solutions of methyl blue,methyl orange,and methylene blue.The results show that the Cu₃Se₂/Cu₂Se/Cu₂O hollow microspheres can be formed via a dissolution-recrystallization regime and possess large ratio of 36:1 of hollow-sphere-diameter:wall-thickness,which is beneficial to increase the specific surface area and improve its photocatalytic activity.The Cu₃Se₂/Cu₂Se/Cu₂O catalyst exhibits excellent photodegradation activity to a high concentration of methyl blue solution.2.The candy-like Cu₄O₃ microstructure has been synthesized successfully by a facile wet chemical method,and it was characterized by XRD,SEM,TEM,XPS,TG-DTA and UV-vis diffuse reflectance absorption spectrum.The influences of the quantities of reactants and reaction time on the morphologies and structures of the product were systematically investigated.The formation mechanism of candy-like Cu₄O₃ was proposed,based on the crystal structure analysis and control experiments.The photodegradation activities to the four dye solutions of methyl blue,methylene blue,rhodamine B and methyl orange,and the antibacterial activities against S.aureus and E.coli were studied.The antibacterial mechanism was investigated by tracing the morphology evolution of the bacteria.These results present that the candy-like Cu₄O₃ microstructure was formed underwent the route of Cu?NH₃?₄²⁺?Cu?OH?₄^2-?Cu?OH?₂?CuO?Cu₄O₃ nuclei?Cu₄O₃ crystal growth?candy-like Cu₄O₃,and optimal reaction conditions are required to obtain the candy-like Cu₄O₃.The candy-like Cu₄O₃ microstructure exhibits excellent photodegradation activity to methylene blue solution and good long-term antibacterial activities to both E.coli and S.aureus bacteria.3.The ball-flower-like CuO was synthesized by a facile wet chemical method,and it was characterized by XRD,SEM,TEM,XPS and TG.The influences of the reaction conditions on the morphologies and structures of the products were explored based on series of control experiments.The antibacterial activities against S.aureus and E.coli bacteria were studied.The results present that the antibacterial rates of S.aureus and E.coli remained above95%in the presence of 2.0 mg of CuO after 72 h of incubation,which indicates that the ball-flower-like CuO exhibits good long-term antibacterial activities.