Fabrication of polyvinylpyrrolidone capped nickel nanoclusters as sensing material for enhanced electrocatalytic oxidation of 2-amino-4-chlorophenol

Abstract

2-Amino-4-chlorophenol (2A-4CP) is a chemical compound with a chlorine-substituted aromatic ring and an amino group; it is a persistent environmental pollutant that poses serious threat to human health. Therefore, its quantification in environmental samples is the need of the hour. This research is focused on the synthesis of polyvinyl pyrrolidone-capped nickel nanoclusters (PVP/Ni-NCs) through a chemical reduction method. The successfully synthesized PVP/Ni-NCs were characterized using advanced analytical techniques, such as scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD) and zeta sizer analyses. SEM and AFM analyses were conducted to evaluate the surface morphology and 3D texture of the prepared PVP/Ni-NCs. XRD and zeta sizer results were utilized for the determination of average particle size of the nanoclusters, which was found 2.95 nm via XRD and 4.513 nm via zeta sizer respectively. The fabricated nanoclusters were used as electrocatalysts for the detection of 2A-4CP. The charge transfer kinetics of PVP/Ni-NCs/GCE was determined using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Moreover, under the optimized conditions (scan rate of 100 mV s⁻¹, BRB electrolyte, pH 4 and potential window from −0.4 to 0.7 V), the fabricated sensor manifested exceptional response to 2A-4CP. In the linear dynamic range from 0.1 to 260 μM, the prepared sensor exhibited the lowest limit of detection of 0.079 μM. The high sensitivity of PVP/Ni-NCs/GCE suggests its efficiency to be utilized for the detection of environmental pollutants at a commercial level.