Graphitic carbon nitride based fluorine-free hydrophobic sponges for the mitigation of microplastics, oil spillage, and harmful microbial growth in water

Water pollution poses significant environmental challenges due to the pervasive presence of microplastics, frequent oil spillage, and the proliferation of harmful microbial populations. Addressing these multifaceted pollution issues often necessitates distinct treatment strategies, potentially compromising the economic viability and causing secondary pollution. In response, this study presents a novel approach by developing three-dimensional sponges with interconnected pores to simultaneously combat these environmental concerns. In this work, Hexadecyltrimethoxysilane functionalized graphitic carbon nitride (h-GCN) hydrophobic sponges were fabricated in a simple and scalable method. The sponges with varying porosity and hydrophobicity were fabricated by controlling the amount of NaCl as the hard sacrificial agent incorporated into the Polydimethylsiloxane matrix. The hierarchical surface irregularity and surface energy of the sponges were influenced by the addition of h-GCN content. The resulting sponges showed remarkable properties of oil/organic solvent-water separation ability of 116 % for mineral oil to 832 % for chloroform. Leveraging their extensive porosity and hydrophobic nature, the sponges demonstrated near-complete removal of Poly (methyl methacrylate) (PMMA) microplastic particles from aqueous solutions. The hydrophobic sponges also showed excellent bacteriostatic properties by inhibiting the growth of Escherichia coli and Staphylococcus aureus. We anticipate that these fluorine-free hydrophobic sponges, with their multifaceted capability to mitigate diverse water pollutants and exhibit robust recyclability, hold promise for a range of environmental remediation applications.