Surfactant-Assisted Synthesis of Praseodymium Orthovanadate Nanofiber-Supported NiFe-Layered Double Hydroxide Bifunctional Catalyst: The Electrochemical Detection and Degradation of Diphenylamine.

Physiological storage disorders are caused by ineffective post-harvest handling of horticultural crops, particularly fruits. To address these post-harvest concerns, diphenylamine (DPAH •+ ) is widely used as a preservative to prevent fruit degradation and surface scald during storage around the world. Humans are negatively affected by the use of high concentrations of DPAH •+ because of the various health complications related to its exposure. As a result, accurate detection and quantification of DPAH •+ residues in treated fruits are critical. Rare earth metal orthovanadates, which have excellent physical and chemical properties, are potential materials for electrochemical sensors in this area. Herein, we present a simple and direct ultrasonication technique for the surfactant-assisted synthesis of praseodymium orthovanadate (PrVO 4 or PrV) loaded on nickel iron layered double hydroxide (NiFe-LDH) synthesized with deep eutectic solvent assistance, as well as its application as an effective catalyst in the detection and degradation of DPAH •+ in fruits and water samples. The current work presents supreme electrochemical features of a PrV@NiFe-LDH-modified screen-printed carbon electrode (SPCE) where cetyltrimethylammonium bromide (CTAB) surfactant-driven fabrication of PrV directs the formation of highly qualified engineered structures and the deep eutectic solvent based green synthesis of NiFe-LDH creates hierarchical lamellar structures following the principles of green chemistry. PrV and NiFe-LDH combine to produce a synergistic effect that improves the number of active sites, charge transfer kinetics, and electronic conductivity. Differential pulse voltammetry analysis of PrV@NiFe-LDH/SPCE reveals a dynamic working range (0.005-226.26 μM), increased sensitivity (133.13 μA μM -1 cm -2 ), enhanced photocatalytic activity, and low detection limit (0.001 μM), which are considered significant when compared with the former reported electrodes in the literature for the determination of DPAḢ + for its real-time applications.