Ball milling synthesis of FeO 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 FeO nanoparticles for the preparation of FeO nanoparticles-functionalized porous boron nitride (FeO/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 FeO nanoparticles on the surface of PBN. The adsorption performance of FeO/PBN toward cationic dyes could be significantly improved while no enhancement was observed for anionic dyes. The great adsorption performance of FeO/PBN is due to its surface functional groups and surface defects formed in the ball milling process. Moreover, the strong interaction force between FeO/PBN and cationic dyes promotes rapid initial adsorption due to their negatively charged surface. Magnetic measurements demonstrated that FeO/PBN is superparamagnetic. The composites with low loadings of FeO 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 FeO/PBN and greatly promotes the practical application of FeO/PBN in the field of environmental purification.