Microwave enhanced Fenton-like process for degradation of perfluorooctanoic acid (PFOA) using Pb-BiFeO3/rGO as heterogeneous catalyst

- MW irradiation shortens the synthesis time of Pb-BFO/rGO.
- Both Pb and GO dopants enhance the catalytic activity of BFO and OH generation.
- PFOA was efficiently decomposed in MW-enhanced Fenton-like process using Pb-BFO/rGO in a short time.

Hybrid nanostructured materials play an increasing role in environmental applications. This study developed a hybrid nanocomposite (Pb-BFO/rGO) using a microwave-assisted hydrothermal method, which grafted Pb-doped BiFeO3 (BFO) nanoparticles on reduced graphene oxide (rGO) sheets. Pb-BFO/rGO was used as a heterogeneous catalyst in a microwave enhanced Fenton-like process (MW-Fenton-like) for the decomposition of perfluoroocatanoic acid (PFOA), a perfluorinated compound present in water bodies with high bioaccumulation and toxicity for human being. The results reveal that Pb-BFO/rGO has large specific surface area (∼84.2 m2 g−1), small crystallite sizes (∼3.3 nm) and multiple functional groups such as carboxyl groups and Fe-O groups. Compared with the bare BFO and Pb-BFO, Pb-BFO/rGO showed greater catalytic efficiencies for H2O2 activation for PFOA degradation with the removal ratio of 90.0% from 30.0 mg L−1 to 50.0 mg L−1 within 5.0 min in the MW-Fenton-like process. Microwave irradiation was shown to significantly influence the degradation of PFOA through energy transfer and cross-coupling reactions. Pb-BFO/rGO absorbed the microwave energy, which facilitated the decomposition of H2O2 and the generation of hydroxy radicals (OH), which is responsible for the PFOA degradation. The degradation pathway of PFOA was investigated by detecting the degradation byproducts using UPLC-MS/MS and ICP/MS. Five kinds of short-chain perfluorinated carboxylic acids and fluoride ion were identified. The overall findings provide new insight into the novel hybrid catalysis for Fenton-like and other water treatment applications.

Schematic representation of degradation of PFOA using Pb-BFO/rGO in MW-Fenton-like process.123