Facile Synthesis of Boron Organic Polymers for Efficient Removal and Separation of Methylene Blue, Rhodamine B, and Rhodamine 6G

Dodecahydro-closo-dodecaborate anion (B12H122-) organic polymers (BOPS) were facilely obtained from aqueous solution via a simple and effective method. Single crystal X-ray diffraction results insinuated that the BOPs were formed by intermolecular forces between 4,4'-bipyridine and B12H122-. The presence of B12H122- gave the BOPs a certain degree of electronegativity, which possessed excellent stability and high adsorption capacity toward the cationic dyes methylene blue (MB), rhodamine B (RB), and rhodamine 6G (RB6G). The adsorption capacity of BOPs for MB, RB, and RB 6G dyes reached 3250 mg.g(-1); 1388 mg.g(-1); and 2033 mg.g(-1), respectively. Through adsorption kinetics and adsorption isotherm results, BOPs exhibited rapid kinetic adsorption and ultrahigh adsorption capacity. Moreover, the BOPs materials could separate MB/MO, MB/RB, MB/RB6G, RB/MO, and RB6G/MO mixed components efficiently by adjusting the pH of the dye solution. It was worth mentioning that BOPs adsorbents could be easily and rapidly regenerated and be recycled at least five times without decreasing the adsorption capacity, indicating a potential application in dye pollutants removal.