Synthesis of honeycomb Ag@CuO nanoparticles and their application as a highly sensitive and electrocatalytically...

Copper acetate/silver nitrate/polyvinylpyrrolidone was first prepared into nano-hybrid silver-doped copper oxide by electrospinning, and then nano-honeycomb particles were produced through heat-treatment. For the first time, honeycomb Ag@CuO nanoparticles were prepared by electrospinning, and a H₂O₂ sensor was constructed by modifying the carbon paste electrode (CPE) with the honeycomb Ag@CuO nanoparticles. This work performed the structural, morphological, and phase analysis of the Ag@CuO nanoparticles by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results indicated the synthesis of Ag@CuO hybrid nanoparticles with high purity, and cyclic voltammetry and amperometry show that the Ag@CuO modified electrode has high electrocatalytic performances with fast voltammetric responses and a notably decreased overpotential compared to that of even the CuO modified CPE. In addition, the Ag/CuO-CPE based H₂O₂ sensor has the highest sensitivity of 1982.14 μA (mmol L^-1)^-1 cm^-2, the lowest detection limit of 0.01 μmol L^-1 ((S/N) = 3), and the measured linear response for H₂O₂ oxidation ranged from 0.05 μmol L^-1 to 100 μmol L^-1 and 100 μmol L^-1 to 1.5 mmol L^-1. The proposed method was applied to the determination of H₂O₂ in coconut fruit samples from canned coconut, and the satisfactory results confirmed the applicability of this sensor in practical analysis.