Electrochemical detection of p-nitrophenol over nickel nanoparticles supported on Longquan lignite-derived mesoporous carbon fabricated by hard template method

Abstract

The efficient and clean utilization of low-rank lignite conforms the strategy of carbon neutral development. Herein, a two-step strategy of hard template method and co-precipitation method was designed to prepare nickel nanoparticles supported on mesoporous carbon (Nix/MPC) using the residue from the ethanolysis of Longquan lignite for quantitative detection of p-nitrophenol (NP). The electrochemical reduction properties of modified glassy carbon electrodes (GCEs) with different nickel loadings (x = 10, 15, and 20 wt%) for NP were compared, in which Ni15/MPC/GCE stood out and presented better conductivity, larger electrochemical active surface area, and faster electron transfer rate. According to the differential pulse voltammetry detection results, Ni15/MPC/GCE displays satisfactory detection limit (1.8 µM) and far wider detection concentration range (170 ∼ 10000 µM) than other reported electrochemical sensors. Moreover, Ni15/MPC/GCE exhibits acceptable stability and reproducibility, and the relative standard deviation of NP detection current is only 0.71% under the interference of 100-fold concentration interfering substances. Hence, the constructed Ni15/MPC/GCE demonstrates a promising electrochemical sensor for detecting NP in environmental sewage.