Robust self-healing slippery liquid-infused porous surfaces containing CeO2@PDA/h-BN nanofillers for effective protection of magnesium alloys

A novel nanofiller-reinforced SLIPS is developed on AZ31 Mg alloys. • CeO 2 @PDA/h-BN nanofillers enhance the corrosion resistance and self-healing properties of coatings. • Self-healing ability is due to rapid lubricant redistribution and passive film formation. • The coating shows better long-term corrosion protection than conventional SLIPSs. Conventional slippery liquid-infused porous surfaces (SLIPSs) have emerged as an effective strategy to protect Mg alloys from corrosion. However, their anti-corrosion and self-healing performances remain insufficient for long-term service. Therefore, multifunctional CeO 2 @PDA/h-BN nanofillers were incorporated into liquid lubricant to fabricate nanofiller-reinforced SLIPSs (CeO 2 @PDA/h-BN-SLIPSs). In particular, this study systematically investigated influences of nanofiller concentrations on surface morphology, hydrophobicity, and electrochemical behavior. CeO 2 @PDA/h-BN-SLIPS-8, prepared at a concentration of 8 mg/mL, displayed the lowest corrosion current density (8.22 × 10 -11 A/cm 2 ) and the highest impedance modulus (9.06 × 10 8 Ω cm 2 at 0.01 Hz). This was ascribed to the synergistic effects of high surface hydrophobicity provided by a lubricant layer, tortuous diffusion pathways provided by h-BN nanosheets, ion-exchange property of MgAl-LDH, and active corrosion inhibition of CeO 2 . In addition, scanning vibration electrode technique (SVET) analysis confirmed good self-healing behavior of CeO 2 @PDA/h-BN-SLIPS-8, arising from both rapid lubricant redistribution and formation of protective cerium-based passive films. Overall, this study provides an effective strategy for fabrication of robust anti-corrosive and self-healing SLIPSs, offering enhanced corrosion protection for Mg alloys in industry.