Interfacial engineering of magnetic particles with porous shells: towards magnetic core – porous shell microparticles

The surface engineering on various functional nanomaterials has enabled the creation of diverse nanocomposites that possess pre-designed architectures with improved and complementary properties. Magnetic porous materials with core-shell structures have recently received great attentions due to the combination of the respective properties of cores and shells that achieves cooperatively boosted performance. Core-shell magnetic nanoparticles are well-known for their outstanding properties of enhanced stability, being able to protect the active species from harsh environments, improved physical, chemical and photoelectric properties, and easiness of surface functionalization, etc. All of their exciting synergistic properties are heavily depending on the controllable and ingenious design towards cores and shells, and precise regulation of the interaction between them. In this paper, different surface engineering strategies,based on sol-gel chemistry and confined interfacial coating, for the construction of iron oxide-mesoporous core-shell materials have been reviewed. Attentions are paid not only on the selection of promising candidates for cores or porous shells and the creation of different shapes, but also more importantly on the synthetic principles and mechanisms for interfacial control in achieving perfectly adjustment of porous shells with various compositions, different pore sizes, pore structures and functionalities. Following the methods and principles presented in the review, it is very easy even for new beginners to synthesize various magnetic porous materials with well-defined core-shell structure and integrated functionalities for various applications.