Surfactant-free synthesis of a Fe3O4@ZIF-8 core–shell heterostructure for adsorption of methylene blue

Abstract

Nanoscale porous metal–organic frameworks and related materials have received considerable attention in recent years due to their widespread applications. However, the effective synthesis of magnetic core–shell MOFs still remains a significant challenge. In this article, a Fe₃O₄@ZIF-8 core–shell nanostructure with unique morphology, a large specific surface area, excellent thermal stability, and superparamagnetic properties is reported. Additionally, instead of using organic surfactants, a surfactant-free and facile synthesis route is successfully developed. The ZIF-8 shell thickness can be precisely controlled by altering the number of growth cycles. Fe₃O₄@ZIF-8 shows good adsorption properties for MB, with maximum adsorption capacity of 20.2 mg g⁻¹.