A multifunctional sponge incorporated with TiO2 and graphene oxide as a reusable absorbent for oil/water separation and dye absorption

Abstract

Water pollution due to various insoluble organic oils and soluble dyes has already threatened the marine ecosystem and human health. In this study, a robust multifunctional, reusable material for the separation of oil/water mixture, and the absorption of insoluble organic oils and soluble dyes has been successfully prepared by functionalizing a melamine sponge with TiO₂, graphene oxide (GO), and stearic acid (SA). TiO₂ nanoparticles and GO sheets with large surface area and high surface roughness provide excellent hydrophobicity. The long hydrophobic –CH₂ chains of SA further enhance the hydrophobicity of the as-prepared sponge. TiO₂–GO–SA sponges with excellent mechanical performance have been successfully used for the separation of oil/water mixture in harsh environment (strong acid and alkali), and for the continuous separation of oil/water. Furthermore, the TiO₂–GO–SA sponge can absorb various oils and dyes. The reusability of the TiO₂–GO–SA sponge was realized by squeezing extrusion and ultraviolet irradiation for the absorption of oils and dyes, respectively. The excellent stability and superior recyclability of the TiO₂–GO–SA sponge make it promising for practical applications in wastewater remediation.