Cu/Cu-M Alloy Catalyst With 1D Nanosturctures:Preparation And Electrochemical Property

High levels of nitrate in environment which poses serious risks to aquatic ecosystem are attracting intensive attentions.One of the hot topic in this field is on the electrochemical technology which can monitor the nitrate in a fast and efficient way.What is crucial for the sensing is to develop the nanostructured electrode favorable for charge transfer and mass transport.In the present thesis,uniform one-dimensional nanostructures with high density are created over Cu wire surface by combining thermal oxidation and electrochemical reduction processing.The high specific surface area and enhanced conductivity improve the sensitivity of the device.The electrochemical performance of pure and Pd alloyed Cu nanowires was also investigated.The main conclusions reached are as follows.(1)The influence of thermal oxidation condictions on nanostructure of copper wires was investigated to elucidate the growth machenism.The final copper oxide nanoswires are converted from Cu2O.And metallic nanowire arrays could be obtained after electrochemical reduction of the oxide nanowires.The heat treatment conditions are optimized as heating at 600℃ with the ramp rate of 10℃/min and holding for 4h in the air.High density nanowires of copper oxides with diameter about 120 nm and length 33.9μm were obtained.(2)The obtained Cu nanowire arrays exhibited good sensing ability for nitrate ions.The linear range for electrochemical detection is between 50 μM-600 μM with sensitivity of 0.357 μA/μM/cm(R2=0.997).Stabilities and a good anti-interference performance to ions including Cl-、HCO3-、SO42-、H2PO4-,and NO2-were also presented.(3)The Cu-Pd alloy nanowires were successfully prepared by using Pd(NO3)2 solution which can protect the nanowire structure and allow the reaction carry out in a more mild manner.The content of Pd is 1.6 at%when the concentration of Pd(NO3)2 solution was 1.0 mM.(4)The electrochemical reduction ability of Cu-Pd alloy nanowires was tested,and the synergistic effect of Cu and Pd on the nitrate reduction process was elucidated.The reduction peak potential shifted positively after adding Pd,indicating that the addition of Pd improves the electrocatalytic activity of the electrode.