Synthesis of Copper and Silver Nanoparticles by Using Microwave-Assisted Ionic Liquid Crystal Method and Their Application for Nonenzymatic Hydrogen Peroxide Determination

Abstract

The non-enzymatic copper (Cu) and silver (Ag)/ionic liquid crystal (ILC)/graphite paste nanocomposite electrodes were designed for the sensitive determination of hydrogen peroxide (H2O2). The microwave-assisted ILC (MAILC) method was applied for the synthesis of Cu or Ag nanoparticles by using the mixture of its corresponding acetate salt and ILC (1, 1′-dialkyl-4, 4′-bipyridinium bis (triflimide) s) for the first time. This route did not employ any additional template agent, surface capping and reducing agents, supporting materials, or also inert atmosphere. The process was fast, simple and high-yielding. ILC can act as the ordered reaction medium, microwave absorber and reducing and stabilizing agents. The synthesized Cu or Ag/ILC nanocomposite was mixed as binder with the appropriate amount of graphite for the fabrication of Cu or Ag/ILC/graphite paste nanocomposite electrode, without any further treatment. This type of ILC has great thermal stability due to the triflimide counter ions that preserves its structure even after microwave treatment. Excellent electrocatalytic effects toward H2O2 were observed for the Cu/ILC/graphite paste nanocomposite electrode compared to Ag/ILC/graphite paste nanocomposite electrode. The results showed the higher electrocatalytic effect of Cu nanoparticles with respect to Ag nanoparticles for the determination of H2O2. The Cu/ILC/graphite paste nanocomposite electrode achieved linear ranges of 4.0 µM to 0.4 mM and 0.4–10 mM with correlation coefficients of 0.9939 and 0.9974, respectively, for H2O2 determination.