Document Type : Research Paper
Chemistry Department, Islamic Azad University, Ayatollah Amoli Branch, Amol, Iran
Oxidation of formaldehyde (HCHO) is very important, owing to its use in fuel cells. Modification of electrodes surfaces is an excellent way to decrease the overpotentials as well as to increase the current density of the voltammetric response.pt as most efficient metal catalyst can easily be poisoned by product of oxidation and also it has high cost. In this work an efficient and low cost electrocatalytic system for electrochemical oxidation of formaldehyde in alkaline solution is introduced. For preparation of this modified electrode, copolymeric film on the surface of carbon paste electrode was formed by successive potential cycling in solution containing o-aminophenol and aniline as monomer and Triton X-100 as a surfactant. Ni(II) ions were incorporated into the electrode surface by immersion of the copolymeric modified electrode in 0.1 M Ni(II) ion solution. The influences of different parameters such as mol ratio of monomers in copolymer formation and the number of potential cycling for copolymer formation on electrocatalytic ability of the modified electrode for formaldehyde oxidation have been investigated and optimized.Results show that modified electrode with copolymeric films, show higher catalytic effect for formaldehyde oxidation respect to pure homopolymers (polyaniline or poly(o-aminophenol)). Also addition of Triton -X100 in electropolymerization step, considerably increased catalytic ability of the modified electrode for formaldehyde oxidation. This modified electrode displays a highly efficient electrocatalytic activity toward oxidation of formaldehyde. The current density of 11 mA cm-2 is greater than most of the previously reported electrodes.