OICC Press Iranian Journal of Catalysis 2345-4865 8 3 2024 02 03 Formaldehyde measurement based on its electrocatalytic oxidation by Ni-TiO2 nanoparticles/chitosan modified carbon paste electrode as an effective method EN Ebrahim Zarei Department of Basic Sciences, Farhangian University, Tehran, Iran. Mohammad Reza Jamali Department of Chemistry, Payame Noor University, Tehran, Iran. Jaber Bagheri Department of Chemistry, Payame Noor University, Tehran, Iran. Journal Article 2024 02 03 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 Ni2+ 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 × 10-1 s-1 and 5.14 × 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 formaldehyde was evaluated and proved. The effects of various factors on the efficiency of electrocatalytic oxidation of formaldehyde were optimized. Under the optimized condition, a calibration curve was obtained in the linear dynamic range of 2.80 × 10-4 to 2.50 × 10-2 mol L-1 with detection limit of 7.14 × 10-5 mol L-1 (3σ/slope) for formaldehyde determination. Also, the method was successfully applied for formaldehyde measurement in the real sample.