Determination of 4-nitrophenol using MoO3 loaded glassy carbon electrode via electrochemical sensing approach

Abstract

In order to raise possible ways of MoO3 synthesis and improve its existing applications, MoO3 nanomaterial was successfully synthesized through the solvo-hydrothermal route by utilizing a mixture of ionic liquid (1-butyl-3-methylimidazolium bromide) as a solvent, and water as co-solvent in 1:1 ratio. The morphology and structural parameters of IL-as­sisted MoO3 product were examined by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). Additionally, the surface wettability and particle size distribution were inspected using the contact angle and dynamic light scattering (DLS) analysis. Glassy carbon electrode (GCE) surface was then modified by IL-assisted MoO3. The formed IL-MoO3/GCE was employed as an electro­chemical sensor for determination of 4-nitrophenol (4-NP), which is very toxic and important pollutant. The redox behavior of 4-NP at the surface of IL-MoO3/GCE was investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. Limits of detection (LOD) and limits of quantification (LOQ) determined from CV were found to be 6.76 and 22.5 mM, while from DPV recordings, 5.41 and 18.0 mM are found. The obtained results clearly reveal possible application of MoO3 for selective and sensitive sensing of 4-NP. The decorated electrode was successfully employed for determination of 4-NP in the river water real samples.

Keywords

• Molybdenium oxide nanoparticles
• ionic liquid
• solvo-hydrothermal synthesis
• nitrophenol
• voltammetry techniques