Ball milling synthesis of Fe 3 O 4 nanoparticles-functionalized porous boron nitride with enhanced cationic dye removal performance

Enhancement of the adsorption performance and recyclability of adsorbents is a crucial aspect of water treatment. Herein, we used one-dimensional porous boron nitride (PBN) as a carrier to load Fe O nanoparticles for the preparation of Fe O nanoparticles-functionalized porous boron nitride (Fe O /PBN) a ball milling method. The high-energy ball milling promoted the creation of a negatively charged PBN surface and facilitated the uniform distribution of Fe O nanoparticles on the surface of PBN. The adsorption performance of Fe O /PBN toward cationic dyes could be significantly improved while no enhancement was observed for anionic dyes. The great adsorption performance of Fe O /PBN is due to its surface functional groups and surface defects formed in the ball milling process. Moreover, the strong interaction force between Fe O /PBN and cationic dyes promotes rapid initial adsorption due to their negatively charged surface. Magnetic measurements demonstrated that Fe O /PBN is superparamagnetic. The composites with low loadings of Fe O nanoparticles could be quickly separated from the aqueous solution under a low applied magnetic field, improving their recyclability. This work highlights the role of ball milling in improving the adsorption performance of Fe O /PBN and greatly promotes the practical application of Fe O /PBN in the field of environmental purification.