Fabrication of NiFe layered double hydroxide/reduced graphene oxide (NiFe-LDH/rGO) nanocomposite with enhanced sonophotocatalytic activity for the degradation of moxifloxacin

Abstract

Herein a NiFe layered double hydroxide/reduced graphene oxide (NiFe-LDH/rGO) nanocomposite was synthesized in a hydrothermal method. The sonophotocatalytic implementation of NiFe-LDH/rGO nanocomposite was scrutinized for the degradation of moxifloxacin (MOX), as a model-emerging contaminant, from the solution. The structure of the synthesized samples was analyzed by XRD, FE-SEM, EDX, TEM, FTIR, BET, PL, and UV-Vis DRS analyses. To manifest the sonophotocatalytic performance of NiFe-LDH/rGO nanocomposite, the impact of the main operating parameters was examined for the degradation of MOX. The best sonophotocatalytic efficiency of 90.40% was achieved by using 1.0 g/L catalyst, 20 mg/L MOX, and an ultrasonic power of 150 W at a pH of 8 (natural) within 60 min. Moreover, the effects of the addition of various oxidants, dissolved gases, and various scavengers on the decomposition of MOX were investigated. A proposed mechanism was also presented for the decomposition of MOX in the presence of NiFe-LDH/rGO nanocomposite under the sonophotocatalytic system. By-products formed through sonophotocatalytic degradation process were recognized by the gas chromatography-mass spectrometry (GC-MS) technique. Finally, the reusability test of NiFe-LDH/rGO nanocomposite in the MOX degradation revealed that a drop of almost 13% occurred after five successive cycles.