Voltammetric sensor based on a Ni-Co-layered double hydroxide/ multi-walled carbon nanotubes nanocomposite for 4-aminophenol determination

In this work, we developed a simple technique to produce an effective electrode material consisting of nickelcobalt-layered double hydroxide/multi-walled carbon nanotubes nanocomposite (Ni-Co-LDH/MWCNTs). This nanocomposite was prepared and characterization techniques such as field -emission scanning electron microscopy (FE -SEM), Fourier-transform infrared (FT-IR) and x-ray powder diffraction (XRD) were used to characterize its morphology and structure. The electrochemical studies and measurements were carried out by using various techniques including cyclic voltammetry (CV), differential pulse voltammetry (DPV), and chronoamperometry (CHA). The Ni-Co-LDH/MWCNTs nanocomposite-modified carbon paste electrode (Ni-Co-LDH/ MWCNTs/CPE) exhibited enhanced electrocatalytic performance for the determination of 4-aminophenol. Detection of 4-aminophenol was done by using DPV. According to the results of DPV, the Ni-Co-LDH/ MWCNTs/CPE sensor demonstrated a linear response to 4-aminophenol in the linear range of 0.02 -700.0 mu M, with a limit of detection (LOD) of 0.01 mu M, and a sensitivity of 0.076 mu A/ mu M. Also, the modified CPE presented reproducible and repeatable responses to determine 4 -AP. The prepared sensor was also applied for determination of 4-aminophenol in the presence of possible interfering species and good results were obtained. In addition, the sensor successfully detected 4-aminophenol in real water samples with recoveries ranging from 98.0 % to 104.0 %, and with relative standard deviation (RSD) below 3.3 %. Therefore, the obtained results indicate that the prepared sensor can be an effective tool for the simple, fast, and sensitive detection of 4-aminophenol in water samples.