Constructing Ti3C2Tx@PPy-MoO4 hybrid reinforced epoxy coating for achieving active-passive collaborative anti-corrosion under deep sea environment

Ti 3 C 2 T x nanosheets, which can act as effective physical barrier against corrosion species, have emerged as promising corrosion-resistant reinforcements in organic coatings due to abundant surface functional groups. However, relying solely on Ti 3 C 2 T x for passive protection does not adequately meet higher corrosion protection requirements, especially under high hydrostatic pressure environment in the deep sea. Herein, we synthesized Ti 3 C 2 T x @PPy-MoO 4 (MPMo) hybrid through in-situ oxidative polymerization strategy, which endowed epoxy coating with collaborative protection of passive physical barrier and active corrosion-inhibition. MPMo enhanced epoxy coating (MPMo/EP) exhibited superior anti-corrosion durability in simulated 60 MPa deep sea environment, maintaining a |Z| f=0.01 Hz value above 10 8  Ω·cm 2 and outperforming Ti 3 C 2 T x -based coatings by three orders of magnitude even after six cycles of AHP test. Moreover, polypyrrole (PPy) significantly improved the structural stability of Ti 3 C 2 T x , and successfully loaded with MoO 4 2− through anion doping. Meanwhile, Raman mapping analysis also revealed that MoO 4 2− anions adsorbed onto the Q235 steel surface and formed Fe 2 (MoO 4 ) 3 protective layers, which significantly hindered the generation of corrosion products. This work achieves active-passive synergistic protection of coatings through in-situ oxidation polymerization, providing a new approach for constructing robust anti-corrosion coatings suitable for higher protection demand in deep sea environment.