Superhydrophobic granular filter media modified with mesoporous nanoparticles for magnetically guided oil cleanup†

The frequent occurrence of marine oil spills and the discharge of oily industrial wastewater have resulted in severe environmental pollution and ecological crises. Conventional oil–water separation methods often struggle to balance high separation efficiency with material recyclability when dealing with large-scale oil contamination. Consequently, the development of efficient, recyclable, and economically viable oil–water separation materials has become an urgent challenge. In this study, a superhydrophobic/oleophilic composite ceramic particle filter medium (OFMSPsC) was synthesized using the chemical grafting method, incorporating mesoporous silica and magnetic Fe₃O₄ nanoparticles. The material surface was further modified with octadecyltrimethoxysilane (OTMS), significantly enhancing its hydrophobicity and stability. Characterization results revealed that OFMSPsC exhibits excellent superhydrophobic properties, with a contact angle of 156.6°, and favorable magnetic responsiveness, with a saturation magnetization of 1.173 emu g⁻¹. Additionally, the material demonstrated outstanding resistance to acidic and alkaline conditions, ultrasonic treatment, and mechanical abrasion. In oil–water separation experiments, OFMSPsC achieved over 93% separation efficiency and maintained stable performance after multiple reuse cycles. Furthermore, the embedded magnetic nanoparticles facilitated rapid recovery of the material using an external magnetic field, greatly enhancing its reusability and operational convenience. Overall, the fabricated OFMSPsC material shows great potential for applications in environmental remediation and industrial oil spill cleanup.