Enhanced catalytic activity of α-FeOOH-rGO supported on active carbon fiber (ACF) for degradation of phenol and quinolone in the solar-Fenton system.

A new heterogeneous solar-Fenton catalyst, α-FeOOH-reduced graphene oxide (rGO) supported on active carbon fiber (ACF), was synthesized via in situ electrophoretic deposition in a self-assembly process. Optimization of the components (electrophoretic deposition time of GO and Fe, GO dosages), the effect of pH and the catalysts stability were investigated systematically. The results indicated that rGO-α-FeOOH composite is formed during the ferrous-ion-induced self-assembly process on ACF. FeOOH-rGO/ACF displayed excellent catalytic activity for degrading phenol and quinoline under the solar-driven photo-Fenton process in a wide range of pH values (4.5-9.5) and possess good stability in neutral condition. The phenol oxidation process on this catalyst was described by a pseudo-first-order kinetics model. Both the ACF support and solar irradiation promoted greater H2O2 decomposition and produced more OH radicals, thus, significantly improving the catalytic capacity. The introduction of graphene improved the catalytic capacity of the catalyst under solar irradiation. The optimal electrophoretic deposition time of GO and the optimal Fe and initial GO content in deposition were 10 min, 9.8 wt% and 15.0 wt%, respectively. The degradation pathways of phenol and quinoline in the solar-driven photo-Fenton process were also elucidated.