Two-dimensional metal-organic framework nanobelts for selective Fe3+ removal from aqueous solution with high adsorption capacity

Ultrathin metal-organic frameworks (MOFs) have emerged as a novel class of two-dimensional materials for their unique properties, such as the larger surface area, enriched unsaturated coordination centers and more accessible active sites, which are beneficial for improving their performances in catalysis, sensing and separation. In this work, the MOF (named YNU-1 nanobelts) was exploited to selectively remove Fe3+ from aqueous solutions, which showed an excellent adsorption performance with the adsorption capacity of 456.37 mg/g. The value is the highest among all reported adsorbents of Fe3+, owing to the coordination between the Fe3+ and abundant carboxyl groups on the surface of YNU-1 nanobelts. The adsorption behavior can be well-described with a pseudo-second-order kinetic model, which revealed a chemisorption process. The alpha-Fe2O3 on the surface of YNU-1 nanobelts after adsorption was confirmed by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and element mapping measurements. The YNU-1 nanobelts was successfully applied for iron treatment in real sample. Our study provided a facile and efficient method for the removal of iron ions from water.