Dark–Light Tandem Catalytic Oxidation of Formaldehyde over SrBi(2)Ta(2)O(9) Nanosheets

Formaldehyde (HCHO), as one of the main indoor toxic pollutions, presents a great threat to human health. Hence, it is imperative to efficiently remove HCHO and create a good indoor living environment for people. Herein, a layered perovskite material SrBi(2)Ta(2)O(9) (SBT), was studied for the first time and exhibited superior photocatalytic efficiency and stability compared to commercial TiO(2) (P25). Furthermore, a unique dark–light tandem catalytic mechanism was constructed. In the dark reaction stage, HCHO (Lewis base) site was adsorbed on the terminal (Bi(2)O(2))(2+) layer (Lewis acid) site of SBT in the form of Lewis acid-base complexation and was gradually oxidized to CO(3)(2−) intermediate (HCHO → DOM (dioxymethylene) → HCOO(−) → CO(3)(2−)). Then, in the light reaction stage, CO(3)(2−) was completely converted into CO(2) and H(2)O (CO(3)(2−) → CO(2)). Our study contributes to a thorough comprehension of the photocatalytic oxidation of HCHO and points out its potential for day–night continuous work applications in a natural environment.