Preparation of K+ intercalated MnO2-rGO composite for the electrochemical detection of nitroaniline in industrial wastewater.

This work reports the electrochemical detection of highly hazardous material 4-Nitroaniline (4-NA) based on the metal oxide-rGO composite materials. The potassium intercalated MnO2-rGO composite material was prepared by a simple one-pot reduction method. The K+ intercalation on K-MnO2-rGO was confirmed by X-ray photoelectron spectroscopy (XPS) and Raman analysis. The amorphous nature of prepared material was scrutinized by high-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED) pattern analysis. The elemental compositions are done by energy dispersive X-ray Analysis (EDX) mapping. The prepared composite material K-MnO2-rGO was used to determine the 4-NA by differential pulse voltammetry (DPV). The electroanalytical performances of fabricated K-MnO2-rGO/SPCE were compared with the K-MnO2 and rGO in pH 7. The developed 4-NA sensor showed good sensitivity (2.85 µA µM-1 cm-2), linear range (0.001-10.53 µM), and LOD (0.7 nM). Furthermore, the K-MnO2-rGO/SPCE exhibited high selectivity with the other potential interfering nitro compounds in river water and pond water samples. Therefore the developed sensor can be applied for the determination of noxious pollutants in real-time monitoring devices.