Electrochemical preparation of nickel-iron hydroxide loaded on multi-walled carbon nanotubes electrode for the detection of urea

A nickel-iron hydroxide/multi-walled carbon nanotubes （MWCNTs）composite film electrode was prepared by electrochemical derivation of metal hexacyanoferrate in alkaline solution. MWCNTs film modified electrode was prepared by dropping method，then Ni-Fe bimetal hexacyanoferrate（Ni-FeHCF）nanoparticles were deposited on the surface of MWCNTs by cyclic voltammetry. This Ni-FeHCF/MWCNTs electrode was electrochemically derived in alkaline solution and a MWCNTs composite film electrode（Ni（OH）2-Fe（OH）3 /MWCNTs/ CCE）was obtained. The surface morphology and the electrochemical behavior of this modified electrode were characterized by scanning electron microscope（SEM）and cyclic voltammetry（CV）. This electrode exhibited high catalytic activity for the electrochemical oxidation of urea under the synergistic action of each component. Based on this，the non-enzymatic electrochemical sensing of urea was established. In 1.0 mol/L KOH solution， the linear range of urea by amperometry was between 5.0×10−3 and 2.8 mmol/L，and the detection limit was 3.6 μµmol/L. The sensitivity to urea was 54.3 μµA/（mmol/L）. This electrode could be used for the determination of urea in river water and human urine samples. © 2022, Youke Publishing Co.,Ltd. All rights reserved.