Ultrasonic-assisted self-assembly of a neodymium vanadate and hydroxylated multi-walled carbon nanotubes composite for electrochemical detection of p-nitrophenol

In recent years, nanocomposites prepared from rare earth metal vanadate and carbon nanomaterials have attracted great attention, and they have shown great promise for electrochemical sensing applications. Herein, a facile ultrasonic-assisted assembly method was adopted to prepare neodymium vanadate/hydroxylated multi-walled carbon nanotubes (NdV/MWCNTs-OH) composite. The morphology, elemental states, crystal structure and functional groups of the composites were investigated through a series of characterizations. Then, a novel electrochemical sensor, NdV/MWCNTs-OH composite modified glassy carbon electrode (GCE), was designed for the detection of p-nitrophenol (PNP). The synergistic effect generated by the combination of NdV and WMCNTs-OH accelerated the charge transfer kinetics and exposed more active sites, which facilitated more effective detection. Under optimized experimental conditions, the as-prepared sensor exhibited a wider linear range (1-200 μM) to PNP, and a lower limit of detection (LOD) of 0.41 μM could be obtained (signal-to-noise ratio of 3; S/N = 3). Furthermore, the sensor was successfully used for the determination of PNP in real samples (industrial wastewater and river samples), and satisfactory recoveries (96.67%-101.88%) with RSDs less than 5% were observed. Herein, the prepared electrochemical sensor has potential application prospect in the analysis and detection of PNP.