Synergistic effects enabled efficient photocatalytic removal of ofloxacin antibiotic in wastewater by layered double hydroxides loaded lignin-derived carbon fibers

The environmental problems caused by the abuse of antibiotics are raising serious attention, and the removal of antibiotics in wastewater is meaningful yet challenging. In this work, lignin-derived carbon fibers loaded layered double hydroxides (LDH@LCF) has been prepared for the removal of ofloxacin (OFX) from wastewater via photocatalysis, which exhibit a high degradation efficiency of 96 % under visible light and maintained 90 % after five reuses. The effects of Zn 2+ /Fe 3+ in the samples and other parameters affecting the photocatalytic efficiency of OFX have been systematically investigated. Results demonstrated that the enhanced photocatalytic efficiency is derived from the synergistic effect of the Zn 2+ and Fe 3+ in the LDH with a reduced band gap of the catalyst, higher number of oxygen and metal unsaturated coordination sites, and rapid removal of photogenerated electrons. The working mechanism and degradation pathways for OFX by LDH@LCF are also elucidated in detail.