Ni–Al/layered double hydroxide/Ag nanoparticle composite modified carbon-paste electrode as a renewable electrode and novel electrochemical sensor for hydrogen peroxide

Abstract

In the present study, a simple and highly sensitive electrochemical method was developed for the determination of hydrogen peroxide (H₂O₂) through a Ni–Al/layered double hydroxide/Ag nanoparticle composite modified carbon-paste electrode (Ni–Al/LDH/Ag NPs/CPE) as a renewable electrode in 0.1 M phosphate buffer solution (PBS, pH = 7.0). Scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray diffraction (XRD) were performed for the characterization of the Ni–Al/LDH/Ag NP composite. The electrocatalytic activity of the Ni–Al/LDH/Ag NPs/CPE for H₂O₂ reduction was studied by cyclic voltammetry and chronoamperometric (at an applied potential of −0.9 V) methods. The prepared renewable modified electrode as a H₂O₂ sensor shows good electrocatalytic activity, fast response time, good stability and reproducibility. The present sensor also displays a linear range from 10 μM to 10 mM concentration of H₂O₂ with a detection limit of 6 μM (S/N = 3) and sensitivity of 1.863 μA mM⁻¹ cm⁻². This sensor was employed successfully for the determination of H₂O₂ in real samples by the chronoamperometric method, which indicates its applicability in practical analysis.