Nanoengineered Titanium Nitride/Black Phosphorus Heterostructure-Decorated Melamine Sponge as a Flame Retardant and Superhydrophobic Sorbent for Adsorption of Marine Oil

Abstract To address the low adsorption efficiency for high-viscosity crude oil and the flammability of adsorbents in marine oil spill treatment, a nanoengineered multifunctional titanium nitride/black phosphorus−polydopamine−melamine sponge (TiN/BP-PDA/MS) with photothermal, flame-retardant, and superhydrophobic properties was fabricated via a simple dip-coating method. Polydopamine (PDA) served as an adhesive layer, while black phosphorus (BP) and titanium nitride (TiN) provided synergistic photothermal conversion and flame retardancy. The results demonstrate that the composite sponge possesses a stable micro−nano rough structure with a water contact angle of 155°, exhibiting excellent superhydrophobic−oleophilic properties and achieving adsorption capacities of 631−1055 kg/m3 for various oils and organic solvents. Under 1.0 kW/m2 illumination, the BP/TiN synergy enabled rapid heating to reduce crude oil viscosity and enhance adsorption efficiency. Cone calorimetry showed that peak heat release rate and total heat release were reduced by 68.7% and 59.8%, respectively, with significant suppression of smoke and CO/CO2 emissions. The flame-retardant mechanism involves gas-phase radical trapping by BP-derived phosphorus radicals and condensed-phase char barrier formation by PDA, TiN, and PDMS. This work achieves synergistic integration of photothermal conversion, adsorption, and flame retardancy, offering a strategy for emergency marine oil spill remediation.