Simultaneous electrochemical determination of hydroquinone and catechol based on three-dimensional graphene/MWCNTs/BMIMPF6 nanocomposite modified electrode

A three-dimensional glassy carbon electrode (GCE) was fabricated from one-dimensional multiwalled carbon nanotubes (MWCNTs) and two-dimensional graphene (GR), using 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6) ionic liquid to improve its dispersibility and stability. This GR/MWCNTs/BMIMPF6 modified GCE was found to be a highly sensitive electrochemical sensor for the simultaneous determination of hydroquinone (1,4-dihydroxybenzene, HQ) and catechol (1,2-dihydroxybenzene, CT). The GR was characterized using a transmission electron microscope. The electrochemical behaviours of HQ and CT at the GR/MWCNTs/BMIMPF6/GCE were investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The chemically modified electrode exhibited excellent electrochemical catalytic activities towards HQ and CT. Linear relationships between the oxidation peak current and concentration of HQ/CT were obtained in the ranges 0.5 μM to 2.9 mM and 0.2 μM to 0.66 mM with detection limits (S/N = 3) of 0.1 μM and 0.06 μM, respectively. This GR/MWCNTs/BMIMPF6/GCE showed many advantages in terms of dispersibility, stability, sensitivity, facility and economy.