Constructing of FeNi3 nano-necklaces intercalated 3D graphene as an efficient and robust heterogeneous catalyst for photo-Fenton degradation of hazardous organic pollutants

In this study, an innovative heterogeneous nanocatalyst of three-dimensional reduced graphene (3DGr)-wrapped FeNi3 nano-necklaces (NNs) was successfully fabricated. The effectiveness and stability of FeNi3 @ 3DGr nanocomposite in a heterogeneous photo-Fenton technique for the removal of organic pollutants such as mal-achite green (MG), methylene blue (MB), diclofenac (DIC), and ibuprofen (IBF) were evaluated. The nanocatalyst degradation efficiency for MG was studied by altering the starting pH value (2.8-7.5), the dosage of H2O2 (25-150 mM), the concentration of MG dye (30-80 mg/l), and the dose of FeNi3 @ 3DGr nanocomposite (0.2-1.0 g/l). Under optimum operating conditions, the FeNi3 @ 3DGr nanocomposite achieved 100% MG removal efficiency with almost 60% total organic carbon (TOC) below 40 min. Moreover, the catalyst revealed significant durability owing to the synergistic effects of the integration of the 3DGr and FeNi3 NNs frameworks, as its removal performance maintained over 80% after seven consecutive degrading cycles with an acceptable degree of leaching iron. The radical scavenger experiment revealed that hydroxyl radical (center dot OH) species are the essential oxidized radicals participating in the photo-Fenton process. Our findings delivered a stable and effective FeNi3 @ 3DGr heterogeneous nanocatalyst with a high removal capacity for organic contaminants from water through the photo-Fenton technique.