Electro-catalytic oxidation of methane at multi-walled carbon nanotubes-Nafion/nickel hydroxide modified nickel electrode

Abstract

A novel chemical modified nickel (Ni) electrode based on multi-walled carbon nanotubes (MWCNTs), Nafion film and nickel hydroxide has been successfully fabricated for methane (CH 4) detection at ambient conditions. The morphology of the MWCNTs–Nafion/Ni(OH) 2 film was characterized by transmission electron microscopy and the electrochemical properties of the Ni modified electrode were studied by cyclic voltammetry. The MWCNTs–Nafion/Ni(OH) 2–Ni electrode showed good catalytic effect on the oxidation of CH 4 in 1.0 M NaOH. In addition, the modified electrode was free from nitrogen and oxygen interferences. When differential pulse voltammetry was applied to the MWCNTs–Nafion/Ni(OH) 2–Ni electrode, a good linear relationship between the oxidation peak current ( i) and CH 4 concentration ( C methane) was obtained: i = 1.841 C methane + 46.25, where i is in μA and C methane is in 0.0–16.0% (v/v). The relative standard deviation for detection of 3.0% (v/v) CH 4 was 1.80% ( n = 5). The proposed Ni modified electrode is anticipated to provide a promising technique to detect CH 4 at ambient conditions.