Pore size regulation of BN fibers and its effect on tetracycline adsorption

Abstract The environmental hazards caused by antibiotics are becoming more and more serious, especially tetracycline antibiotics, which not only destroy the water balance, but even threaten people's lives. Therefore, the hierarchical micro‐mesoporous boron nitride (BN) fibers with high adsorption capacity were prepared by in situ synthesis. The results indicated that the pore size extremes of the hierarchical micro‐mesoporous BN fibers were distributed at 1.2, 2.9, and 23.4 nm, and the total pore volume reached 0.295 cm 3 /g. Importantly, mesopores were conducive to diffusion while microporous structure was conducive to capture the tetracycline molecules. The maximum adsorption capacity of hierarchical porous BN fibers for tetracycline reached 870.29 mg/g, which was 1.99 times the maximum adsorption capacity reported in the existing literature. This was attributed to the synergistic enhancement between the mass transfer trapping effect and the intermolecular bonding in the BN fibers, which enabled the vertical adsorption of tetracycline molecules on the surface and between the layers of the BN molecules. In addition, the adsorption removal rate of the hierarchical porous BN for tetracycline was still as high as 99.93% after reusing five times. This hierarchical micro‐mesoporous BN fiber has broad application prospects in the fields of antibiotic adsorption and water purification.