Formaldehyde measurement based on its electrocatalytic oxidation by Ni-TiO2 nanoparticles/chitosan modified carbon paste electrode as an effective method

In this work, for the first time, a new and effective bulk modified carbon paste electrode (CPE) was prepared by TiO2 nanoparticles and chitosan and then Ni-2(+) ions were incorporated to this electrode by immersion of the modified electrode in nickel chloride solution. The values of electron transfer coefficient, charge-transfer rate constant and electrode surface coverage for Ni(II)/Ni(III) redox couple of the TiO2/chitosan modified carbon paste electrode (Ni-TiO2/CHIT/CPE) were found to be 0.66, 3.28 x 10(-1) s(-1) and 5.14 x 10(-8) mol cm(-2), respectively. The prepared Ni-TiO2/CHIT/CPE material was characterized by scanning electron microscopy and X-ray diffractometry. The electrochemical behaviour of the Ni-TiO2/CHIT/CPE towards oxidation of founaldehyde was evaluated and proved. The effects of various factors on the efficiency of electrocatalytic oxidation of founaldehyde were optimized Under the optimized condition, a calibration curve was obtained in the linear dynamic range of 2.80 x 10(-4) to 2.50 x 10(-2) mol L-1 with detection limit of 7.14 x 10(-5) mol L-1 (3 sigma/slope) for formaldehyde determination. Also, the method was successfully applied for formaldehyde measurement in the real sample.