Electrocatalytic oxidation of formaldehyde and formic acid at Pd nanoparticles modified glassy carbon electrode

Pd nanoparticle (NP) modified glassy carbon electrodes were prepared by the electrochemical deposition method of cyclic voltammetry (CV) and the potentiostatic technique, respectively. Scanning electron microscopy was used to characterise the morphology of the NP-modified electrode´s surface. The electrocatalytic oxidation of formaldehyde and formic acid were investigated at the modified electrodes by CV and linear sweep voltammetry. The experimental results show that the electrodes display remarkable electrocatalytic activity and long-term stability for the oxidation of formaldehyde and formic acid. The oxidation mechanism of formaldehyde and formic acid on the modified electrodes is discussed primarily. The experimental parameters were optimised for establishing the methods of formaldehyde and formic acid determination. The oxidation peak current is linearly proportional to the concentration of formaldehyde in the range of 1.0 × 10^-4 -1.4 × 10^-2M with the detection limit being 3.0 × 10^-5M and relative standard deviation (RSD) being 3.9%. The linear dynamic range of formic acid is in the range of 1.0 × 10^-5-1.0 × 10^-2 M, the detection limit is 4.0 × 10^-6 M and the RSD is 2.8%. The low detection limit, wide linear range and high sensitivity of the sensors make them valuable for further application.