Electrochemical Properties Of Composite Ordered Micro/Nano Arrays By Template Method

The preparation of electrochemical sensors based on nanomaterials is a frontier subject currently.Especially,the preparation of new electrochemical sensors with high sensitivity,low cost,simple operation,low detection requirements and repeatable utilization has become a research hotspot.The synthesis of composite metal nanomaterials is an important research direction in the field of non-enzymatic biosensors.Among these nanomaterials,two-dimensional nanofilms,as a new kind of functional materials,have many applications in industry,military and other fields.In this thesis,two-dimensional colloidal sphere templates were prepared by self-assembly method,and metal micro/nano porous arrays were then obtained by means of electro-deposition on the templates.Another material was grown on the as-prepared metal micro/nano arrays by means of electro-deposition or magnetron sputtering method,and finally the composite micro/nano arrays were obtained.The corresponding morphology,structure and composition were characterized by SEM,XRD,XPS and EDS.The electrochemical performance was studied by electrochemical analyzer.The specific research content is as follows:?1?Construction of CuO/Au micro/nano array and its electrochemical performance: At First,a two-dimensional polystyrene colloidal sphere template was prepared by self-assembly method.Its morphology was observed through SEM and the result showed that it was arranged in a hexagonal compact packing in a large area with a ball diameter of 500 nm.Au micro/nano array was then synthesized by means of electrodeposition method based on the above template,and its morphology and composition were characterized.The results indicated that Au micro/nano array also presented a hexagonal compact arrangement with high order.Thereafter,Cu was deposited on the Au micro-nano array by means of electro-deposition.The CuO/Au micro/nano array was finally obtained through heat treatment,and its morphology wasanalyzed.The electrochemical performance was studied by the electrochemical analyzer,and the results showed that CuO/Au ordered micro/nano array had excellent performance as a new type of glucose sensor,with the sensitivity up to 4099.6 ?A?m M^-1cm^-2,and had good anti-interference.?2?Construction of Ni/Au micro/nano array and its electrochemical performance:Firstly,Au micro-nano array was prepared by constant-current electrodeposition method with the assistant of PSS templates.Secondly,Ni/Au ordered micro/nano array was fabricated by electrodepositing of Ni on the surface of Au micro/nano array.We find when the deposition time of Ni is 3 minutes,the obtained sample has the best catalytic activity.Because in this time,the Ni layer was completely covered on the surface of Au micro/nano array with a small thickness.So the product would have a specific surface area and good electrical conduction.Electrochemical test results showed that the sensitivity of Ni/Au ordered micro-nano array to AA was 354 ?A?m M^-1cm^-2 with good stability.?3?Construction of Ta/Ni microcavity array and its electrochemical performance:A novel Ta/Ni microcavity array was successfully synthesized through monolayer polystyrene sphere template.That is,Ni bowl-like array film was first deposited into the template by electrochemical method.After dissolving the polystyrene spheres,Ta microcavity array film was deposited onto the Ni array by magnetron sputtering.Morphology observation revealed that the prepared Ta/Ni film was formed by a large number of bowl-like cavities with centre hole,which were arranged in hexagonal close-packed order.Combined with a gold layer sputtered on a glass substrate,this Ta/Ni microcavity array film can be used as an electrochemical electrode for the amperometric detection of uric acid.It exhibited a high sensitivity of 886?A?m M^-1cm^-2,a detection limit of 0.1 ?M,and a wide linear range from 1 ?M to 1.4m M.A possible mechanism was also given in the paper.The results demonstrate that the Ta/Ni microcavity array film is a promising new platform for the construction of non-enzymatic uric acid sensors.