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The Photocatalytic Efficacy of Potassium Hydroxide–Based Modification of Titanium Dioxide in the Oxidative Destruction of Gaseous Formaldehyde
Author(s) -
Cho MyeonSeong,
Vikrant Kumar,
Boukhvalov Danil W.,
Kim KiHyun
Publication year - 2025
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.202501387
Subject(s) - potassium hydroxide , photocatalysis , formaldehyde , titanium dioxide , chemistry , formate , potassium , oxygen , surface modification , inorganic chemistry , nuclear chemistry , photochemistry , materials science , catalysis , organic chemistry , metallurgy
Abstract Formaldehyde (FA) is a carcinogenic oxygenated volatile organic compound and a key constituent of indoor air pollution. Photocatalytic oxidation (PCO) is a promising strategy for managing FA in indoor environments. Here, the PCO of FA in indoor air has been investigated by modifying TiO 2 with KOH (KOH/TiO 2 : expressed as KT‐x, where x = the molar concentration of KOH from 0.1–2 m ). The KOH treatment achieves superior FA removal performance of KT‐0.1 over TiO 2 (e.g., space‐time yield: 1.78E−03 versus 9.91E−04 molecules photon −1 mg −1 and dynamic clean air delivery rate: 10 versus 5.43 L mg −1 min −1 ). Such differences in photocatalytic activity reflect an enhancement in charge separation, molecular oxygen activation (on the photocatalyst surface), and electron mobility facilitated by the presence of surface hydroxyl groups and potassium on the TiO 2 surface. On the KT‐x surface, the PCO of FA proceeds through several reactive intermediates (e.g., formate and dioxymethylene). According to density functional theory, the PCO of FA by KT‐x is promoted by the synergistic combination of oxygen vacancies and potassium impurities on the TiO 2 surface. This research offers valuable insights into the development of cost‐effective photocatalysts with enhanced PCO performance.