Application of Synthesized NaA Nanozeolite as a Novel Supported Electrode for the Formaldehyde Electro‐catalytic Oxidation

Abstract

Nickel hydroxide doped NaA nanozeolite carbon paste electrode (Ni(OH)2‐NaA/CPE) was employed as simple and efficient sensor for electro‐catalytic oxidation and detection of formaldehyde (HCHO). For this goal, organic template free synthesis of NaA nanozeolite under room‐temperature was performed and characterized. Field emission scanning electronic microscopy (FESEM) technique exhibited the presence of spherical NaA nanozeolite morphology with particle size under 100 nm. The BET surface area and average pore diameter of synthesized NaA nanozeolite were obtained to be 3.622 × 102 m2 g−1 and 5.9 nm, respectively. Carbon paste electrode (CPE) was modified by NaA nanozeolite and then Ni2+ ions incorporated to this electrode to obtain Ni‐NaA/CPE. The values of electron transfer coefficient and mean value of catalytic rate constant for HCHO and redox sites of Ni(OH)2‐NaA/CPE were caculated to be 0.58 and 8.42 × 106 cm3 mol−1 s−1, respectively. The results indicate that Ni(OH)2‐NaA/CPE displays good electrocatalytic activity with respects to HCHO oxidation owing to its mesoporous structure and the large surface area of NaA nanozeolite. Moreover, amperometric studies exhibited that the fabricated electrode has a detection limits of 2.0 μM allowing the quantitative analysis of HCHO in the concentration range from 6.0 × 10−3 to 2.31 × 10−1mM with high sensitivity (1.6716 × 103 μA mM−1).

Recent Advances in Electrochemical Sensors for Formaldehyde

“…Furthermore, zeolite materials exhibit molecular sieving properties, selectively adsorbing or allowing the target analyte to diffuse back into the air, thereby improving selectivity in detection. Later on, Hassaninejad-Darzi used synthesized NaA nanozeolite for modifying a carbon paste electrode (CPE) and introduced nickel ions (Ni 2+ ) to the electrode, resulting in a Ni(OH) 2 -NaA/CPE electrode [ 124 ]. By loading nickel hydroxide onto the porous structure and large surface area of NaA nanozeolite, the electrode’s electrocatalytic activity was enhanced.…”