The electrochemical sensor for methanol detection using silicon epoxy coated platinum nanoparticles

A platinum (Pt) nanoparticle-based electrochemical sensor has been applied for the detection of methanol in methanol fuel cells. The platinum nanoparticles were electrodeposited on glassy carbon (GC) in HCl containing hydrogen hexachloroplatinate using cyclic voltammetry. The size and distribution of the nanoparticles were found to be dependent on the deposition parameters, such as the concentration of platinum ions, scan rate, and number of cycles. The deposited platinum nanoparticles were spin-coated with silicone epoxy (SE), and scanning electron microscopy (SEM) confirmed the deposition. The concentration of methanol was determined by a double potential step chronoamperometric method using the SE/Pt/GC electrode at the oxidation potential of +0.60 V vs. Ag/AgCl electrode. The sensor exhibited a long-term stability for 40 h repeat using and has an advantage that adsorption of CO was eliminated by use of SE film. The dynamic range of the analytical method was determined to be from 2.5 × 10−4 to 10.0 M in two slopes with a detection limit of 1.0 × 10−4 M.