Surfactant-Assisted Synthesis of Praseodymium Orthovanadate\nNanofiber-Supported NiFe-Layered Double Hydroxide Bifunctional Catalyst:\nThe Electrochemical Detection and Degradation of Diphenylamine

Abstract

Physiological\nstorage disorders are caused by ineffective post-harvest\nhandling of horticultural crops, particularly fruits. To address these\npost-harvest concerns, diphenylamine (DPAH^•+) is\nwidely used as a preservative to prevent fruit degradation and surface\nscald during storage around the world. Humans are negatively affected\nby the use of high concentrations of DPAH^•+ because\nof the various health complications related to its exposure. As a\nresult, accurate detection and quantification of DPAH^•+ residues in treated fruits are critical. Rare earth metal orthovanadates,\nwhich have excellent physical and chemical properties, are potential\nmaterials for electrochemical sensors in this area. Herein, we present\na simple and direct ultrasonication technique for the surfactant-assisted\nsynthesis of praseodymium orthovanadate (PrVO₄ or PrV)\nloaded on nickel iron layered double hydroxide (NiFe-LDH) synthesized\nwith deep eutectic solvent assistance, as well as its application\nas an effective catalyst in the detection and degradation of DPAH^•+ in fruits and water samples. The current work presents\nsupreme electrochemical features of a PrV@NiFe-LDH-modified screen-printed\ncarbon electrode (SPCE) where cetyltrimethylammonium bromide (CTAB)\nsurfactant-driven fabrication of PrV directs the formation of highly\nqualified engineered structures and the deep eutectic solvent based\ngreen synthesis of NiFe-LDH creates hierarchical lamellar structures\nfollowing the principles of green chemistry. PrV and NiFe-LDH combine\nto produce a synergistic effect that improves the number of active\nsites, charge transfer kinetics, and electronic conductivity. Differential\npulse voltammetry analysis of PrV@NiFe-LDH/SPCE reveals a dynamic\nworking range (0.005–226.26 μM), increased sensitivity\n(133.13 μA μM^–1 cm^–2), enhanced photocatalytic activity, and low detection limit (0.001\nμM), which are considered significant when compared with the\nformer reported electrodes in the literature for the determination\nof DPAḢ⁺ for its real-time applications.