Photothermal Self‐Healing Black g‐C3N4 Nanosheet‐Based Coatings: A Novel Approach for Enhanced Anticorrosion and Antibiofouling Protection

Abstract Multifunctional coatings have great application value in the protection of Marine equipment, ships and ship facilities, but they still suffer from the disadvantages of high preparation cost and complicated synthesis methods. Herein, employing a simple method to synthesize black carbon nitride (BCN), as the filler in polydimethylsiloxane (PDMS) to construct BCN/PDMS composite coating with a multifunctional anti‐corrosion/antifouling coating capable of photothermal self‐healing property. Experimental results exhibit that the BCN/PDMS coating can still possesses excellent corrosion resistance after 28 d of immersion in the simulated seawater, and the impedance modulus still manages to reach 6.991 × 10 7 Ω cm 2 , and the scratches on the coating can be healed within 90 min in the photo‐thermal self‐repairing experiments as well. In addition, the BCN/PDMS coating also presents favorable resistance to anti‐biofouling in the anti‐algae test, with only a small amount of algae adhering to the surface. This work explores the application and technological innovation of g‐C 3 N 4 ‐based materials in multifunctional coatings and provides new ideas and methods.