Electronic modulation of porous boron nitride via C/O co-doping for enhanced tetracycline adsorption

The persistent contamination of aquatic systems by tetracycline antibiotics necessitates the development of efficient and sustainable adsorbents. Herein, a one-step deep eutectic solvent (DES) strategy is developed for the synthesis of carbon/oxygen co-doped hexagonal boron nitride (BCNO) nanosheets, using a ternary DES (H 3 BO 3 /urea/guanidine hydrochloride) as an all-in-one precursor and self-templating medium. The resulting BCNO material exhibits an ultrahigh tetracycline adsorption capacity of 428.5 mg g −1 . In situ pyrolysis analysis combined with theoretical simulations reveals that the DES-guided process facilitates synergistic heteroatom doping and the formation of a hierarchically porous structure enriched with Lewis acid-base sites. The adsorption process follows a multilayer chemisorption mechanism, driven by the concerted contribution of π-π stacking, hydrogen bonding, and Lewis acid-base coordination. The material exhibits excellent regenerability, retaining >85% of its original adsorption efficiency after five consecutive cycles. This work not only presents a scalable and eco-friendly route to functional BN nanomaterials but also provides fundamental insights into the molecular-level design of high-performance adsorbents for environmental remediation.