Ni-MOF-doped superhydrophobic sponge with photothermal conversion properties for enhanced removal of oil pollutants and microplastics from aqueous environments

Microplastic (MPs) and oil spills have emerged as critical global environmental challenges due to their persistence, bioaccumulation, and difficulty with their removal from aquatic ecosystems. These pollutants not only deteriorate aquatic environments but also pose significant risks to human health via the food chain. Consequently, developing efficient removal technologies is essential for environmental protection and ecosystem recovery. To this end, a superhydrophobic sponge material (PPNP) based on melamine foam (MF) was prepared using a simple dipping method. The sponge was coated with polydopamine (PDA), Ni-MOF, polypyrrole (PPy), and polydimethylsiloxane (PDMS) in layers, endowing it with photothermal conversion capability, superhydrophobicity (WCA = 154.5°) and the ability to adsorb MPs. Tests showed that PPNP exhibited excellent photothermal conversion performance under different light conditions, with surface temperatures reaching up to 135.1℃, thus enhancing crude oil recovery efficiency through photothermal-assisted methods. Additionally, PPNP demonstrated outstanding performance in removing MPs from water, with a removal efficiency as high as 98.4 %. Furthermore, density functional theory (DFT) calculations were employed to analyze the various forces involved in the adsorption of MPs by the composite sponge, considering the material’s properties. The prepared composite sponge provides an efficient and environmentally friendly solution for the removal of environmental pollutants, demonstrating broad application potential.