Sustainable preparation of graphene-analogue boron nitride by ball-milling for adsorption of organic pollutants

摘要

The method of fabricating low-cost adsorbents with high activity and durability via a convenient and ecofriendly procedure is of great importance to wastewater treatment. Herein, a high-efficient mechanical exfoliation strategy was proposed to facilely prepare few-layered graphene-analogue boron nitride(BN) via a one-step non-organic solvent assisted wet ball mill procedure. Ball-milling treatment increased the specific surface area of BN 3.5-fold by reducing the thickness to ~3 layers with 45 min. The exfoliated BN exhibited strikingly improved sorption performance to organic contaminants with around 124% and 116% increased removal efficiency respectively for oxytetracycline(OTC) and Rhodamine B(RhB) as compared to the bulk BN. Batches sorption experiments showed that the sorption processes were thermodynamic endothermic, and well fitted to pseudo-second-order kinetic model and Freundlich isotherm equation. The π-π stacking interaction, hydrophobic effect and electrostatic interaction were proposed as the dominated sorption mechanism. In addition, no significant decline in adsorptive removal ability for the sorbent after 5 times recycling. The results indicate that the ball-milling exfoliation is a fast, green,sustainable and promising strategy for synthesis of highly potent BN based two-dimensional layered adsorbents.