The self-powered cathodic protection effect of flexible PDMS-based piezoelectric composites in a simulated pressure-alternating marine environment

The development of a self-sufficient protection system is crucial for alloys in deep sea, due to the presence of water pressure, short of electricity, etc. This study underscores the composite with carbonized polydopamine-coated PZT in the polydimethylsiloxane base (cPDA-coated PZT/PDMS) as a self-powered protection solution for alloys in pressure-alternating marine environments. This composite can convert pressure into electrical energy, providing cathodic protection for Q235 in marine environments. The results demonstrate that the composite exhibits excellent electrical output properties. Under cyclic pressure, the composite could generate a current of 22.5 μA, reducing the potential of Q235 to −760 mV and effectively decreasing its corrosion rate, thus offering autonomous cathodic protection. •PZT@cPDA/PDMS provides a self-powered corrosion protection of metals in pressure-varying marine environments.•The composite harnesses pressure and converts it into electrical energy for cathodic protection.•The composite significantly reduces the OCP of Q235 without additional power sources or sacrificial anodes.