| Scanning electrochemical microscopy (SECM) is a new electrochemical technology with high resolution. The SECM can be used to study the corrosion electrochemical system, and some very important information can be got, which cannot be obtained using the conventional electrochemical methods. The SECM has been applied in studying the space surface topography of the corrosive electrode, the electrochemical heterogeneous character and the chemical species, and so on. So the SECM can be used to study dynamic process of the corrosive electrode. The SECM can also be used to study the local breakdown of passive film, the growth of the passive film and the mechanism of the initiative corrosion. The SECM can study the mechanism of the initiation and propagation of corrosion in the micrometer or nanometer space resolution in situ thoroughly, thus the mechanism of the corrosion can be researched from the integrative average level to the micrometer or nanometer space resolution level.In this paper, the SECM tip was made of a platinum wires sealed in glass capillary, the substrate is an iron electrode (99.99%). The concentration of corrosion products was investigated in neutral aqueous solution. The area scanning, line scanning, approach curve and the cyclic voltammetry on iron surface can be obtained using SECM. Among the above experiment methods, the area scanning, line scanning and the approach curve can be used to investigate the concentration profiles of the corrosion products above the iron surface.The main work is as follows:1. The concentration profiles of the corrosion products in different conditions in neutral aqueous solutionAt different tip potentials, the area scanning and line scanning were did, the results showed that the ferrous can be easily oxidized at the tip while the substrate is at the open circuit potential. The results show that the concentration of the aqueous solution influences the experimental results greatly.2. Analysis of the cyclic voltammetry... |
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