Preparation of Magnetic Composite Hollow Microsphere and Its Adsorption Capacity for Basic Dyes

Abstract

Magnetic microspheres with an Fe3O4 core and a SiO2–TiO2 hybrid shell were prepared by a surfactant-assisted aerosol process and subsequent etching treatment. The core–shell spheres with robust and chemically stable Ti–O–Si shells exhibit excellent adsorption performance toward basic dyes. The maximum adsorption capacities were obtained at 147 mg/g for methylene blue (MB) and 124.6 mg/g for basic fuchsin. MB with an initial concentration of 20 mg/L can be completely removed in 5 min at a dosage of 0.5 mg/L, and the equilibrium time is 90 min in the MB concentration range 20–250 mg/L. The adsorption kinetics follows the pseudo-second-order model. Furthermore, the dye saturated microspheres can be easily recycled by an external magnetic field and regenerated using 1–3 wt % NaOH aqueous solution. After six recycle runs, 98% of the adsorption capacity was still retained. The low-cost magnetic hollow spheres with good adsorption capacity are a promising candidate for water treatment.

Superior Adsorption and Regenerable Dye Adsorbent Based on Flower-Like Molybdenum Disulfide Nanostructure

“…When PH = 14 alkaline solution was applied, the removal efficiency still remained 83.9% in comparison the efficiency of pure MoS 2 is 98.5%, meaning that the adsorption ability can be easily recovered by alkaline solution. According to the zeta potential, the excellent desorption performance at alkaline solution can be attributed that excessive OH − ions compete with the activated adsorption sites of the cationic RhB molecules, leading to the desorption of RhB from MoS 2 through ions exchange 48 . It is confirmed that the feasibility of reuse for the MoS 2 with full adsorption of RhB molecules by using alkaline solution, which is applicable in its practical water treatment applications.…”

Superior adsorption performance for triphenylmethane dyes on 3D architectures assembled by ZnO nanosheets as thin as ∼1.5 nm

“…It is found that the adsorption capacities of the present ZnO flower-like architectures for AF and MG are significantly higher than that of adsorbents reported previously, and the adsorption capacity of the ZnO architectures for AF is the highest of all adsorbents for dyes. The adsorption capacity of the ZnO flower-like architectures for BF is higher than cellulose [55], porous silica [56], pmesoporous Si/C composite [57] and other adsorbents [58][59][60][61][62], only lower than mesoporous carbon [11]. These comparative results demonstrated that the present ZnO flower-like architectures are excellent adsorbents for triphenylmethane dyes offering great potential for the dye removal in wastewater.…”

“…Apparently, the adsorption capacities of AF, MG and BF are higher than that of AR and CR. For comparison all the adsorption capacities for AF [9,[40][41][42][43], MG [2,10,25,28,[44][45][46][47][48][49][50][51][52][53][54][55] and BF [11,[56][57][58][59][60][61][62] reported in literature onto various adsorbents are collected and summarized in Table 1. It is found that the adsorption capacities of the present ZnO flower-like architectures for AF and MG are significantly higher than that of adsorbents reported previously, and the adsorption capacity of the ZnO architectures for AF is the highest of all adsorbents for dyes.…”

Decontamination of cationic and anionic dyes in single and binary mode from aqueous phase by mesoporous pulp waste

“…The reason for the relatively high adsorption capacity of MPW is most probably related with the fact that it has the higher surface area and relatively higher carbon content. The pore volume of MPW (0.8108 cm 3 g 21 ) is much higher than the molecular size of MB (1.43 nm 3 0.50 nm 3 0.4 nm) and MO (0.31 nm 3 0.55 nm 3 0.18 nm) [41]. Hence, dyes molecules can easily penetrate into the mesopores of MPW.…”