Fabrication of a novel biochar decorated nano-flower-like MoS2 nanomaterial for the enhanced photodegradation activity of ciprofloxacin: Performance and mechanism

The aggregation of MoS 2 nanoparticles and inefficient electron-migration limit their application for antibiotic removal. In this study, pomelo peel biochar (BC) with smooth surface structure was used as the matrix for loading nano-flower-like MoS 2 microspheres. The as-prepared nanocomposites were used to improve the removal efficiency of ciprofloxacin (CIP). A series of characterizations revealed that the optimal weight ratio of BC to MoS 2 was 3:35 (MoS 2 -BC 3/35 ). MoS 2 -BC 3/35 with narrow-bandgap (1.60 eV) possessed efficient light-utilization ability and the photodegradation efficiency toward CIP was 92.01%, whereas the CIP removal efficiency by MoS 2 was 44.50%. The improvement of this efficiency was attributed to the reduction of electron-hole pairs recombination. More attractively, superoxide radical (·O 2 − ) played a major role during the photocatalytic reaction, because the conduction band potential of MoS 2 -BC 3/35 (-0.81 eV) is lower than the potential of O 2 /·O 2 − (-0.33 eV). Overall, MoS 2 -BC 3/35 is a promising photocatalyst owing to its eco-friendliness, high-efficiency and easy-preparation.