Electrochemical Sensing Based on Metal–Organic Frameworks-Derived Carbon/Molybdenum Disulfide Composites with Superstructure and Synergistic Catalysis

Metal-organic frameworks (MOFs)-derived nanocomposite has attracted extensive attention due to its tunable nanoscale cavities and high chemical tailorability. Herein, with the aim of developing a sensitive electrochemical sensor for p-nitrophenol, a novel MOFs-derived nanocomposite was prepared by the solvothermal method using Zr-MOFs, thiourea, and sodium molybdate as raw materials. By controlling the growth mode and reaction time, the nanohybrids displayed a superstructure composed of MOFs-derived carbon (MOFs-C) and MoS2. Scanning electron microscopy images indicated that MOFs-C/MoS2 was a flower-like porous sphere. Transmission electron microscopic images showed that the MOFs-C/MoS2 had a unique arrow target-like structure. The porous structure held great promise for the fast mass transfer into the material, while the layer-by-layer distributed carbon and MoS2 provided a great structure for the synergistic catalysis. The electrochemical oxidation of (hydroxyamino)phenol to nitrosophenol, which is an important process for the electrochemical behavior of p-nitrophenol, can be selectively catalyzed by the MOFs-C/MoS2. Therefore, the electrochemical sensor based on the MOFs-C/MoS2 material exhibited excellent analytical performance in the determination of p-nitrophenol. Using the technique of square wave voltammetry, the peak current varied quantitatively with the presence of p-nitrophenol in the wide concentration range of 0.5-500 μM. Furthermore, the electrochemical sensor exhibited good practicability in real sample analysis.