Surface-tuned hierarchical ɤ-Fe2O3–N-rGO nanohydrogel for efficient catalytic removal and electrochemical sensing of toxic nitro compounds. (April 2021)

• Record Type: Journal Article
• Authors: Ramu, A.G.; Salla, Sunitha; Gopi, S.; Silambarasan, P.; Yang, D.J.; Song, M.J.; Ali, Hayssam M.; Salem, Mohamed Z.M.; Choi, Dongjin
• Is Part Of: Chemosphere. Volume 268(2021)
• Publication Date: 2021-04
• Subjects: Nanohydrogel -- Spinel nanocrystals -- 2D-graphene oxide -- Electrochemical sensor -- Catalytic reduction; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2020.128853
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: 4- Nitrophenol (4-NP) is a top rated hazardous environmental pollutant and secondary explosive chemicals. For the sake of ecology and environment safety, the catalytic reduction and detection of 4-NP is highly important. In this work, ɤ-Fe2 O3 -nitrogen doped rGO (ɤ-Fe2 O3 –N-rGO) nanohydrogel was synthesized by green hydrothermal method. The morphology and phase purity of prepared ɤ-Fe2 O3 –N-rGO nanohydrogel were confirmed by various analytical (SEM, TEM, XRD, and XPS) and electrochemical techniques. The morphological structure of ɤ-Fe2 O3 –N-rGO nanohydrogel confirmed that the nanocrystals are well covered over the 2D N-rGO layer. Further, ɤ-Fe2 O3 –N-rGO nanohydrogel was applied for the catalytic reduction and electrochemical detection of ecotoxic 4-NP. A low cost, ɤ-Fe2 O3 –N-rGO nanohydrogel displayed an excellent catalytic activity, high recyclability (>5 cycles) and high conversion efficiency of 4-NP to 4-Aminophenol (4-AP). In addition, ɤ-Fe2 O3 –N-rGO nanohydrogel modified GCE displayed a wide linear sensing range (0.1–1000 μM), and a low detection limit (LOD) of 0.1 μM with excellent sensitivity, high selectivity (<1.2%) and good stability (>4 weeks). The developed sensor electrode shows the low reduction potential of −0.3 V and −0.60 V for the determination of 4-NP. The proposed ɤ-Fe2 O3 –N-rGO nanohydrogel is promising catalyst for the detection and removal of toxic aromatic nitro compounds in real site applications. Graphical abstract: Image 1 Highlights: A low cost ɤ-Fe2 O3 –N-rGO nanohydrogel was prepared via hydrothermal method. ɤ-Fe2 O3 –N-rGO nanohydrogel exhibits a tremendous catalytic removal of 4-NP. ɤ-Fe2 O3 –N-rGO nanohydrogel exhibits high reduction efficiency more than 5 cycles. Sensor electrode shows the low detection potential (−0.3 V), (−0.60 V) for 4-NP.