High-performance Fe3O4-terephthalaldehyde magnetic-nanocomposite for removal phenanthrene and 9-phenanthrol: A comprehensive experimental and theoretical analysis

Ascribing to the serious environmental and health risks caused by phenanthrene (PENE) and its dangerous degradation intermediate, 9-phenanthrol (9-PENE), solving their contamination problem was extremely urgent. In this work, a novel Fe3O4-terephthalaldehyde (Fe3O4-TERE) magnetic nanomaterial was fabricated by introducing aromatic rings onto Fe3O4 nanoparticles through encapsulation and grafting technique. The Fe3O4 core provided convenience for the subsequent recycling and regeneration. The grafted aromatic carbons could act as adsorption active sites to form 7C-7C interaction with PENE/9-PENE's aromatic rings, thus improving the capture performance. The properties of the prepared magnetic nanomaterials were investigated via multiple characterization techniques. As expected, the Fe3O4-TERE could be utilized for effectively reducing the contamination risk of PENE and 9-PENE. Furthermore, the Fe3O4-TERE possessed with excellent regeneration performance. The abundant homogeneous reaction sites of Fe3O4-TERE provided possibility for the monolayer adsorption of PENE and 9-PENE. There were multiple microscopic interactions and driving forces jointly or individually participated the multi-stage adsorption reaction. Moreover, density functional theory calculations not only analyzed the validity and existence form of the 7C-7C interaction under different adsorption configuration modes, but also provided deeply perspectives related to the microscopic bonding mechanism. This work proposed a promising fabrication strategy for magnetic nanomaterials used for removing and remediation of polycyclic aromatic hydrocarbons contamination, as well as provided profound theoretical perspectives for analyzing the adsorption mechanism.