Signal-amplified electrochemical monitoring of 4-chlorophenol in water environments based on Ni-BDC decorated multi-walled carbon nanotubes

Developing rapid and reliable electrochemical monitoring methods for 4-CP is of great significance to ensure the safety of the water environment. Electrochemical sensing materials with high sensitivity and selectivity are urgently needed. Here, interlaced sheet-like Ni-BDC frameworks (BDC: 1,4-dicarboxybenzene) and multi-walled carbon nanotubes (MWCNTs) composite (Ni-BDC/MWCNTs) are constructed via in-situ self-assembly of Ni-BDC in the presence of MWCNTs at room temperature . Because of the large specific surface area , high electrochemical activity of Ni-BDC, and the outstanding electrical conductivity of MWCNTs, the obtained Ni-BDC/MWCNTs compound had a significant signal enhancement effect for the oxidation of 4-CP based on the large electrochemical active area, fast electron transfer ability, strong accumulation ability, and high electrocatalytic rate. It was found that the electrochemical oxidation of 4-CP involved the transfer of an electron and a proton. A wide linear range (0.1–50 and 50–500 μM), low detection limit (16.5 nM), high reproducibility, strong stability, and good selectivity were achieved at the Ni-BDC/MWCNTs sensing platform. It also has been successfully used to monitor 4-CP in different river water samples, and got similar results compared to HPLC, which provides promising potential for application in water environment safety monitoring and protection.