Хеміхромні властивості плівок NiOOH в розчинах формальдегіду

• Дата: 2018
• Автори: Fomanyuk, S. S., Smilyk, V. O., Kolbasov, G. Y.
• Формат: Стаття
• Мова: Українська
• Опубліковано: Chuiko Institute of Surface Chemistry National Academy of Sciences of Ukraine 2018
• Теми: хеміхромний ефект; гідроксид нікелю; формальдегід
• Онлайн доступ: https://www.cpts.com.ua/index.php/cpts/article/view/456
• Назва журналу: Chemistry, Physics and Technology of Surface

In order to develop sensory and electrochromic materials, the optical properties of NiOOH films in formaldehyde solutions were studied. At the interaction of these two substances, the NiOOH reduction to Ni(OH)2 and the formaldehyde oxidation to formic acid is carried out. Therefore, NiOH is perspective to use in the form of thin films for express analysis of formaldehyde. The deposition of films was carried out by electrochemical reduction of nitrate ions on a cathode with formation of OH–, which interacts with Ni2+.The optical properties of the obtained films were studied using an assembled stand on the basis of a spectrophotometer C302 in solutions of formaldehyde. The stand allowed determining the kinetics of changing the color of the films in the presence of formaldehyde. The study of kinetics optical changes of NiOOH films in aqueous solution of formaldehyde showed that their chemical interaction changed NiOOH coloration. It has been that the dependence of the changes light transmission in time ?Т/?t is linear in the concentration range of formaldehyde 0.5–20 mmol/l. Determination of formaldehyde concentrations less than 0.5 mmol/l requires 5 to 10 min as dependent on the content of formaldehyde in water. Definition of higher formaldehyde concentrations (22 mmol/l and more) is possible by the absolute value of light transmission. An analysis of cyclic dependences of electrochemical oxidation of Ni(OH)2 to NiOOH and its recovery under influence of formaldehyde shown that the determination of the concentration of formaldehyde of more than 22 mmol/l is possible in the absolute value of light transmission. Comparing the kinetics of chemical and electrochemical decoloration of NiOOH films in 0.1 M NaOH has shown that chemical decoloration by the formaldehyde occurs faster. These properties of the NiOOH films can be used in the development of formaldehyde sensors and electrochromic devices.