Effect of rGO loading on Fe₃O₄: A visible light assisted catalyst material for carbamazepine degradation

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>Carbamazepine (CBZ), an anticonvulsant drug, is one of the most recalcitrant pharmaceuticals detected in wastewater. For the photocatalytic degradation of CBZ, visible light assisted heterogeneous Fenton-like hybrid composites were synthesized via a co-precipitation method by anchoring magnetite (Fe<SUB>3</SUB>O<SUB>4</SUB>) with reduced graphene oxide (rGO). The rGO loading not only reduced the aggregation of Fe<SUB>3</SUB>O<SUB>4</SUB> nanoparticles, but also increased the adsorption capacity of the hybrid composites. The mass ratio of rGO in the composites substantially affected CBZ photocatalytic degradation and a 10 wt% rGO loading (rGF10) provided nearly complete CBZ degradation within 3 h. Moreover, the addition of rGO reduced the charge recombination of the bare Fe<SUB>3</SUB>O<SUB>4</SUB> nanoparticles and provided more accessible reactive sites, enhancing the degradation capacity. The visible light excited Fe<SUB>3</SUB>O<SUB>4</SUB> nanoparticles yielded reactive species such as hydroxyl radicals (·OH), holes (h<SUP>+</SUP>), and superoxide radicals (O<SUB>2</SUB>·<SUP>−</SUP>) during the photodegradation process that were evaluated by using specific scavengers during the degradation experiment. The hybrid catalyst was effective under wide pH ranges (from 3 to 9) and showed faster degradation rates in the acidic condition. The composites were magnetically separable, easily regenerated, and exhibited considerably high photocatalytic activity up to five cycles.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A Fenton-like composite was synthesized by co-precipitation method. </LI> <LI> The composite photochemically degraded CBZ molecule under solar light. </LI> <LI> Certain amount of rGO loading in magnetite increased the photodegradation capacity. </LI> <LI> A 10 wt% rGO loading was optimum to get highest degradation capacity. </LI> <LI> The composite was reusable and the TOC removal was high after the reaction. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>