A porous carbon material doped with an iron species (Fe/PC) was prepared by carbonizing a mixture of zeolitic imidazolate framework-8 in the presence of iron(II) ions. The resulting material was characterized by X-ray diffraction, nitrogen adsorption isotherms, transmission electron microscopy, and by Raman and X-ray photoelectron spectroscopy. Fe/PC was the deposited on the surface of glassy carbon electrode (GCE) to obtain a sensor for amperometric determination of phenolic compounds. The unique catalytic activity, good electrical conductivity and hierarchical structure of the Fe/PC composite results in good electrooxidative activity towards hydroquinone (HQ; typically at 44 mV) and catechol (CC; typically at 160 mV). Under optimal conditions, the amperometric responses are linear in the range from 0.1 to 120 μmol · L-1 for HQ, and from 1.0 to 120 μmol · L-1 for CC. The respective detection limits are 14 and 33 nmol · L-1. The sensor is highly selective against potential interferents and was successfully applied to the determination of HQ and CC contents in (spiked) water samples. Graphical abstract An amperometric sensor for phenolic compounds was constructed by using a metal-organic framework derived iron doped porous carbon material.
Keywords: Cyclic voltammetry; Differential pulse voltammetry; Electrochemical sensor; Metal-organic framework; Nitrogen doping; ZIF-8.