Room-Temperature Synthesis of Magnetic Metal–Organic Frameworks Composites in Water for Efficient Removal of Methylene Blue and As(V)

Magnetic metal–organic framework composites (MFCs) were prepared in water at room temperature through a simple, low-cost and green strategy only by employing organic salts as anionic linker sources. Amino-functionalized MFCs (MFC-N) with different amino group contents were successfully prepared by varying the ratio of disodium of 2-aminoterephthalic (NH2-Na2BDC)/terephthalic acid (Na2BDC). The prepared nanoscale MFC-N-X (X represents the percentage of NH2-Na2BDC, i.e., X = 0, 50, and 100) showed high surface area, large pore volume, excellent magnetic response, and good water and thermal stability. Among these prepared MFC-N-X, MFC-N-100 exhibited the highest adsorption capacity of 358 mg g–1 for methylene blue (MB) and 71 mg g–1 for As(V) due to its porous structure and abundant amino groups. The prepared MFC-N-100 was successfully applied to remove MB and As(V) from different water samples (tap water, lake water, and domestic sewage) with a high removal efficiency and a rapid separation of the sorbent f...