Nitrogen and phosphorus co-doped porous carbon framework with superior electrochemical activity for naphthol isomers sensing

Heteroatom-doped carbon has emerged as one of the most important electrode materials for electrochemical analysis. Thus, designing and synthesizing novel heteroatom-doped carbon material with superior electrochemical activity is highly desired. Herein, we report a simple and effective pyrolysis-activation strategy to synthesize nitrogen and phosphorus co-doped porous carbon (N, P-C) framework by using zeolitic imidazolate framework-67 (ZIF-67) as the precursor and phytic acid as the phosphorus source. It is found that the surface defect level, electrochemical active area and electrode reaction kinetics of N, P-C framework is greatly boosted compared with ZIF-67 derived N-doped porous carbon (N-C) framework. These features endow N, P-C framework with outstanding electrochemical activity for the oxidation of highly toxic environmental pollutants 1-naphthol and 2-naphthol. The oxidation peak currents of 1-naphthol and 2-naphthol increase linearly in the range from 25 nM to 2 μM. Besides, the limits of detection are estimated to be about 8.0 nM and 7.2 nM (three signal-to-noise ratio) for 1-naphthol and 2-naphthol with sensitivity of 87.3 μA μM-1 cm-2 and 84.6 μA μM-1 cm-2, respectively.