Tailoring metal-organic frameworks for the photocatalytic degradation of formaldehyde in indoor environments

초록

Formaldehyde (FA) is a pervasive and harmful indoor air pollutant that poses significant health risks. While photocatalytic oxidation is a promising technology for its abatement, conventional photocatalysts, including pristine metal-organic frameworks (MOFs), suffer from limitations such as rapid electron-hole recombination and a narrow light absorption range. This review systematically summarizes and critically analyzes the recent progress in modifying MOF-based materials to enhance their photocatalytic efficiency for gaseous FA degradation. The primary modification strategies are detailed, including the construction of MOF/semiconductor heterojunctions (e.g., Z-scheme and step (S)-scheme), plasmonic enhancement via the incorporation of noble metal nanoparticles, defect engineering to create unsaturated metal sites and bimetallic active centers, and the integration of polar or carbonaceous materials to build internal electric fields and facilitate charge transport. Mechanistic insights are discussed, highlighting the crucial synergistic role of the MOF adsorption capability to capture and concentrate reactants, along with charge separation pathways that lead to the generation of reactive oxygen species. Furthermore, the successful translation of these advanced powdered materials into practical application formats such as functional coatings and flow-through air filters is examined, with a focus on their performance, stability, and durability. Finally, this review outlines the persistent challenges related to cost, scalability, and standardization, and provides a forward-looking perspective on the future research directions needed to bridge the gap between laboratory breakthroughs and real-world application.

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