Study on Corrosion of Macroporous Silicon in Sodium Hydroxide Solution by Electrochemical Methods and Scanning Electron Microscopy

The fabricated macroporous silicon with a porosity of 26.33% corrosion in NaOH solution was systemically investigated by open circuit potential measurements, linear polarization measurements, potentiodynamic polarization measurements, and scanning electron microscopy, respectively. Results show that the potential open circuit and linear polarization resistance decreases with the NaOH concentration increasing. The corrosion potential shifts significantly to more negative potentials and corrosion current density increases with NaOH concentration increasing. Adding ethanol to 1.0 M NaOH can lead to the linear polarization resistance decrease, corrosion potentials shift in the positive direction, and corrosion current density increase. In addition, the scanning electron microscopy images demonstrate that the macroporous silicon samples are seriously damaged by 1.0 M NaOH and 1.0 M NaOH/EtOH (30%).