Exceptional levofloxacin removal using biochar-derived porous carbon sheets: Mechanisms and density-functional-theory calculation

•Biochar-derived porous carbon nanosheets have prepared via a facile method.•A fast and high LFC removal performance was achieved by PCS-900.•The adsorption capacity of PCS-900 was much higher than the present materials.•PCS-900 exhibited efficient removal in ambient factors and real water matrices.•Comprehensive investigation of interfacial mechanism was presented.