Enhanced adsorption of fluoroquinolone antibiotics on Cu-modified porous boron nitride nanofibers in aqueous solution

•Cu modified porous boron nitride nanofibers was prepared by a simple process.•BNNF-Cu shows excellent removal percentage for 20 mg L−1 OFL (99.74%).•The adsorption fitted pseudo-second-order kinetics and the Freundlich isotherm well.•BNNF-Cu can be used in harsh environments.•Cu can mainly improve chelation and cation bridging interaction.