Design and fabrication of nitrogen-doped tungsten trioxide-based 4-nitrobenzene sensor

In this study, we reported the fabrication of NB sensor using nitrogen-doped tungsten trioxide (N@WO₃) as electrocatalyst. Simple synthetic protocols have been used to obtain the N@WO₃ nanoparticles (NPs). The crystallinity of the N@WO₃ NPs was determined by obtaining its powder X-ray diffraction. The surface structural properties of the N@WO₃ NPs were studied by using scanning electron microscopy. The oxidation states and the presence of N, W, and O elements were checked by X-ray photoelectron spectroscopy and energy-dispersive X-ray spectroscopy, respectively. In further investigations, screen printed (SP) electrode has been modified by employing N@WO₃ NPs as electrode material via drop-casting technique. The catalytic activities of the N@WO₃ NPs-coated SP electrode (N@WO₃/SP) are studied by employing cyclic voltammetry and linear sweep voltammetry. The obtained results demonstrated the presence of decent results for the electrochemical sensing of NB by utilizing N@WO₃/SP as the working electrode in the three-electrode assembly system. N@WO₃ NPs acted as electrocatalyst toward the determination of NB. The N@WO₃/SP electrode showed the detection limit of 0.09 µM with sensitivity of 1.94 µA/µM.cm² and storage stability of 28 days. The N@WO₃/SP also exhibits remarkable selectivity, repeatability, and reproducibility which offers its potential applications in the development of cost-effective and environmental friendly NB sensors.