Fe-MOF derived graphitic carbon nitride nanocomposites as novel electrode materials for the electrochemical sensing of 2,4-dichlorophenol in wastewater

Chemical pollutants found in wastewater pose a significant health risk to human health and the environment. Indeed, there are ongoing efforts to detect, sense and remove chemical pollutants from wastewater. Hence, this work aimed to fabricate an electrochemical sensor using Fe-MOF-based g-C3N4 nanocomposites which was applied in the analysis of 2,4-dichlorophenol (2,4-DCP) in wastewater samples. The metal centers (Cu/Fe/Zn)-MOF-derived g-C3N4 nanocomposite materials were synthesized by an in-situ solvothermal approach and used in the modification of bare-screen-printed carbon electrode (SPCE). The materials were characterized using FESEM, EDS, HRTEM, XRD, FTIR, XPS, TGA/DSC, CV and EIS. The lower Rs (0.62 kΩ) and Rct (0.44 kΩ) values were observed for Fe-MOF/g-C3N4/SPCE than for g-C3N4/SPCE, Cu-MOF/g-C3N4/SPCE and Zn-MOF/g-C3N4/SPCE which implies that the electrochemical performance was significantly improved. Moreover, the surface area, conductivity, as well as charge-transfer capacity of the Fe-MOF/g-C3N4/SPCE were also highly improved. Furthermore, the hybrid nanocomposites material-based electrode exhibited outstanding efficiency in the electrochemical sensing of 2,4-DCP. The Fe-MOF/g-C3N4/SPCE showed a nanomolar limit of detection of 1.2 nmol L−1 with a dynamic concentration range (0.5–200 µmol L−1) for sensing of 2,4-DCP. The utilization of Fe-MOF/g-C3N4-based SPCE towards electrochemical detection of 2,4-DCP in wastewater was evaluated and found to be highly efficacious, with recovery of 95–104%. These results were further validated using a high-performance liquid chromatography. As such, the proposed electrode material could have significant potential for environmental monitoring of 2,4-DCP in wastewater samples.