Ultrasensitive and simultaneous determination of p-Nitrophenol and p-Nitrobenzoic acid by a modified glassy carbon electrode with N-rich nanoporous carbon derived from ZIF-8

Abstract

The preparation process of NCP and application for determination of p -NP and p -NBA. • Aromatic hydrocarbon pollutants with nitro groups are highly toxic and believed as carcinogenic. • Nitrogen-rich mesoporous NCP with large specific surface area was prepared. • An electrochemical sensor for the determination of p -NP and p -NBA have fabricated by used the NCP. • The electrochemical sensor showed outstanding electrochemical performance for p -NP and p -NBA. • The data indicated that this is a promising method for accurate and fast detection of p -NP and p -NBA. Herein, ZIF-8 was synthesized at room temperature and nanoporous carbon particle (NCP) components were produced through direct carbonization of ZIF-8 under a nitrogen atmosphere. In order to study the morphological and structural features of as-prepared NCP, scanning electron microscopy (SEM), nitrogen sorption measurements, and X-ray photoelectron spectroscopy (XPS) were carried out. The NCP had a large surface area (1135.79 m 2 ∙g −1 ) and narrow pore-size distribution (3–5 nm). Modified glassy carbon electrodes with Nafion-containing nanoporous NCP components were applied to fabricate a sensor for electrochemical detection of p -Nitrophenol and p -Nitrobenzoic acid by linear sweep voltammetry. The reductive peak currents of these analytes were observed at −0.325 and −0.187 V. These peaks linearly increased when p -Nitrophenol and p -Nitrobenzoic acid concentrations were in the 0.05–80 μM and 0.03–50 μM ranges. The corresponding detection limits were 17 and 10 nM, respectively. It was speculated that the wide linear range and low detection limits were attributed to the large surface area and porosity as well as rich in nitrogen of the NCP. The sensor was used for the simultaneous analysis of p -Nitrophenol and p -Nitrobenzoic acid in real samples.