Facile construction of multifunctional 3D smart MOF-based polyurethane sponges with photocatalytic ability for efficient separation of oil-in-water emulsions and co-existing organic pollutant

Water resources are increasingly being damaged by human activities, and it is crucial to deal effectively with polluted water resources. Due to the diversity of pollution sources (oil, organic dyes, and other complex pollutants), it makes sense to develop a material that can handle these pollutants simultaneously. In this article, we construct a simple and fast method to fabricate multifunctional superhydrophobic polyurethane sponges (PU). A superhydrophobic composite coating constructed from ZIF-8, polydimethylsiloxane (PDMS), and stearic acid (SA) was attached to the surface of the polyurethane sponge by a simple impregnation method. Through the above process, we have successfully integrated oil–water separation, photocatalysis, and superhydrophobicity into a polyurethane sponge. The results showed that the PDMS/SA/ZIF-8 polyurethane sponge (PSZPU) had a high hydrophobicity angle (162.9 ± 1.1°). In addition, PSZPU maintains high oil–water separation performance (mean value of separation efficiency > 94.24 %) and superhydrophobicity after oil–water separation cycling tests and a series of harsh environmental tests in acidic and alkaline solutions, high temperatures, abrasion, and UV aging irradiation. Overall, the creation of PSZPU provides a new application for superhydrophobic sponges in water resource treatment.