## 1 Introduction  
Ionic liquid is an ionic compound composed of organic cations and organic or inorganic anions, caused by the asymmetry of the volume and structure of anions and cations, and their delocalized positive charges reduce the interactions between anions and cations, making packing crystallization difficult; ionic liquids have a low melting point and present a liquid state at or near room temperature. Ionic liquids have unique physical and chemical properties, such as non-volatile properties, high electrical conductivity, excellent solubility and good stability; therefore, they are a popular topic in green chemistry research and have been widely studied in catalysis [1], adsorption [2], extraction and separation [3,4], and electrochemistry [5,6]. However, ionic liquids have some application issues, such as easy loss and difficult separation, which greatly limits their use. In order to solve these problems, many researchers have carried out research on loaded ionic liquids. A loaded ionic liquid refers to a solid substance with an ionic liquid structure obtained by physically or chemically loading the ionic liquid on organic or inorganic materials, such as polymers [7], magnetic materials [8], and silica gel [9]. Among them, magnetic materials have attracted extensive attention due to their excellent properties, such as large specific surface area, high surface reactivity, high catalytic efficiency, strong adsorption performance, and magnetic response. [PERSON] et al. [8]. prepared novel magnetic ionic liquid-based nanocomposites  
[NiFe\({}_{2}\)O\({}_{4}\)@BMSI]Br and [NiFe\({}_{2}\)O\({}_{4}\)@BMSI]HSO\({}_{4}\) with 1-butylimidazole, (3-bromopropyl)-trimethoxy silane and NiFe\({}_{2}\)O\({}_{4}\) nanoparticles for use in catalytic vegetable oil exchange to prepare biodiesel, which showed a good catalytic activity and regenerative utilization. [PERSON] et al. [10]. determined lead in drinking water by FI-ICP-OES after the preconcentration of ionic liquid-modified magnetic nanoparticles. [PERSON] et al. [11]. synthesized multifunctional magnetic chitosan-graphene oxide-ionic liquid ternary nanohybrids with Fe\({}_{3}\)O\({}_{4}\), chitosan and 1-octyl-3-vinylimidazolium bromide for the efficient adsorption of alkaloids. [PERSON] et al. [12]. synthesized Fe\({}_{3}\)O\({}_{4}\)@SiO\({}_{2}\)@ILs with Fe\({}_{3}\)O\({}_{4}\), tetraethyl silicate and 1-butyl-3-methylimidazolium monosodium phosphate, which could rapidly extract Hg\({}^{2+}\) from natural water with the aid of ultrasound. [PERSON] et al. [13] modified the SiO\({}_{2}\)-coated magnetic core with 3-chloropropyltrimethoxysilane, and then modified it with N-methylimidazole-hexafluorophosphate. The synthesized material was used to adsorb paraquat in water, showing a good dispersion stability and adsorption performance. Sunset yellow (FCF) is one of most common used dyes in varies of the industry. It is a monoazide disulfonated hydroxyl dye extracted from petroleum and mainly used in food production for juice, soft drinks, candy, jellies and salty snacks, giving it a yellow-orange color [14]. Studies have shown that FCF may have the following adverse effects: allergies, attention deficit, and hyperactivity [15]. Understanding how to remove FCF from water is extremely necessary. The adsorption method is regarded as one of the most promising and effective methods because of its simple operation, low cost and no other harmful substances. Many adsorbent materials have been applied to the removal of FCF, such as mesoporous molecular sieves, commercial activated carbon [16; 17], chitosan, graphene [18], or more complex nanocomposites, such as magnetic nanoparticles, modified halloysite nanotubes/poly([2-propylene] acyloxy)ethyl]trimethylammonium chloride) hybrid particles [19], magnetically functionalized graphene oxide, and cetyltrimethylammonium bromide nanocomposites, etc. [20]. However, most of these studies show a low adsorption capacity and unsatisfactory regeneration performance, which needs to be improved.