A sensitive electrochemical sensor based on the partial thermal decomposition of MIL-53(Fe) and reduced graphene oxide for phenol detection

The application of metal organic frameworks (MOFs) in electrochemical sensing has aroused great interest. However, it is still a great challenge to improve their poor conductivity. Here, we reported a novel phenol electrochemical sensor based on Fe2O3/MIL-53(Fe)/rGO, which was fabricated by the thermal decomposition of MIL-53(Fe). The composition and morphology of Fe2O3/MIL-53(Fe)/rGO were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), SEM, and mapping analysis. Meanwhile, the electrochemical behaviors of phenol on the Fe2O3/MIL-53(Fe)/rGO/GCE were investigated by cyclic voltammetry and linear sweep voltammetry. Under optimized conditions, Fe2O3/MIL-53(Fe)/rGO/GCE had enhanced electrocatalytic activity toward phenol due to the larger surface area and excellent conductivity of the Fe2O3/MIL-53(Fe)/rGO. The electrochemical sensor exhibited a wide linear range (0.5–600 μM) and a low detection limit (0.1 μM) as well as good reproducibility and stability. The proposed sensor has also been applied for the determination of phenol in the refinery wastewater samples with satisfactory results.