Relatively uniform and accelerated degradation of pure iron coated with micro-patterned Au disc arrays

• Patterned Au disc array films were deposited on the surface of pure iron.
• The corrosion current density was 4 times larger than that of the uncoated one.
• The corrosion mode turned into macroscopically uniform corrosion.
• Provided a new approach to actively control the degradation mode and rate

Pure iron has been proven to be a potential biodegradable metal, but its degradation rate was too slow. To accelerate its biodegradation, micro-patterned Au disc films were deposited on the surface of pure iron by vacuum sputtering. The influence of Au disc films on the degradation of pure iron matrix in vitro was investigated in the present study. Electrochemical measurement results indicated that the corrosion current density of pure iron coated with micro-patterned Au disc films in Hank's solution was 4 times larger than that of the uncoated one, while the difference between the influences of micro-patterned Au discs with different diameters on the corrosion rate of pure iron was insignificant. Immersion test indicated that the corrosion depth for pure iron coated with Au disc films was about three times as that of bare pure iron. Both electrochemical test and immersion test revealed that the corrosion of pure iron matrix coated with Au disc array became more uniform.